V. Biryukova, G. Sharp, C. Klitis, Sarah Ruddell, M. Sorel
Silicon-on-Insulator devices are particularly sensitive to fabrication errors. As an example, a deviation in waveguide height or width of as little as 1nm translates directly to a 1nm offset in the transfer function of any interferometric devices (such as a ring resonator) constructed using the said waveguide. Therefore, even as fabrication tolerance continues to improve, post-fabrication treatment is often the only way of ensuring device uniformity for particularly demanding applications. This work proposes a novel approach for post fabrication trimming of SOI devices based on localised laser annealing of HSQ cladding layer. HSQ is a versatile material often used in fabrication of SOI devices as both the mask material for electron-beam lithography resist and as a cladding or planarization layer due to its similarity to conventional silica. However, unlike silica, the refractive index of HSQ can be changed significantly (up to ΔnHSQ = 3.26*10-2) by thermal processing. We utilise this property for trimming by cladding a conventional SOI waveguide optimised for TE propagation (height h=220 nm, width=500nm) with a layer of HSQ and then permanently changing the refractive index of the cladding via laser annealing. This approach allows us to select individual devices and only apply the change where necessary. As a demonstrator, we trim a resonance of a racetrack resonator by 1.3nm. The technique has proven to be robust with no parameter drift observed 7 days after trimming and no thermal cross-talk to neighbouring devices. Furthermore, unlike its predecessors, it is based on a standard fabrication process and does not require expensive specialised equipment.
{"title":"Trimming of silicon-on-insulator devices via localised laser annealing (Conference Presentation)","authors":"V. Biryukova, G. Sharp, C. Klitis, Sarah Ruddell, M. Sorel","doi":"10.1117/12.2507212","DOIUrl":"https://doi.org/10.1117/12.2507212","url":null,"abstract":"Silicon-on-Insulator devices are particularly sensitive to fabrication errors. As an example, a deviation in waveguide height or width of as little as 1nm translates directly to a 1nm offset in the transfer function of any interferometric devices (such as a ring resonator) constructed using the said waveguide. Therefore, even as fabrication tolerance continues to improve, post-fabrication treatment is often the only way of ensuring device uniformity for particularly demanding applications. This work proposes a novel approach for post fabrication trimming of SOI devices based on localised laser annealing of HSQ cladding layer. HSQ is a versatile material often used in fabrication of SOI devices as both the mask material for electron-beam lithography resist and as a cladding or planarization layer due to its similarity to conventional silica. However, unlike silica, the refractive index of HSQ can be changed significantly (up to ΔnHSQ = 3.26*10-2) by thermal processing. We utilise this property for trimming by cladding a conventional SOI waveguide optimised for TE propagation (height h=220 nm, width=500nm) with a layer of HSQ and then permanently changing the refractive index of the cladding via laser annealing. This approach allows us to select individual devices and only apply the change where necessary. As a demonstrator, we trim a resonance of a racetrack resonator by 1.3nm. The technique has proven to be robust with no parameter drift observed 7 days after trimming and no thermal cross-talk to neighbouring devices. Furthermore, unlike its predecessors, it is based on a standard fabrication process and does not require expensive specialised equipment.","PeriodicalId":21725,"journal":{"name":"Silicon Photonics XIV","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87690571","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhenzhou Cheng, Tinghui Xiao, Ziqiang Zhao, Wen Zhou, Chin-Yao Chang, S. Set, M. Takenaka, H. Tsang, K. Goda
Mid-infrared (MIR) resonators with high quality (Q) factors play crucial roles in a variety of applications in nonlinear optics, lasing, biochemical sensing, and spectroscopy by virtue of their features of long photon lifetime as well as strong field confinement and enhancement. Previously, such devices have been mainly studied on silicon integration platforms while the development of high-Q germanium resonators is still in its infancy due to quality limitations of current germanium integration platforms. Compared with silicon, germanium possesses a number of advantages for MIR applications, such as a wider transparency window (2 - 15 µm), a higher refractive index (~4), and a higher third-order nonlinear susceptibility. Here we present our experimental demonstration of two types of MIR high-Q germanium resonators, namely, a microring resonator and a photonic crystal nanobeam cavity. A maximum Q factor of ~57,000 is experimentally realized, which is the highest to date on germanium platforms. Moreover, we demonstrate a monolithic integration of the high-Q germanium resonators with suspended-membrane waveguides and focusing subwavelength grating couplers. Our resonators pave a new avenue for the study of on-chip light-germanium interactions and development of on-chip MIR applications in sensing and spectroscopy.
{"title":"Mid-infrared high-Q germanium resonators (Conference Presentation)","authors":"Zhenzhou Cheng, Tinghui Xiao, Ziqiang Zhao, Wen Zhou, Chin-Yao Chang, S. Set, M. Takenaka, H. Tsang, K. Goda","doi":"10.1117/12.2508139","DOIUrl":"https://doi.org/10.1117/12.2508139","url":null,"abstract":"Mid-infrared (MIR) resonators with high quality (Q) factors play crucial roles in a variety of applications in nonlinear optics, lasing, biochemical sensing, and spectroscopy by virtue of their features of long photon lifetime as well as strong field confinement and enhancement. Previously, such devices have been mainly studied on silicon integration platforms while the development of high-Q germanium resonators is still in its infancy due to quality limitations of current germanium integration platforms. Compared with silicon, germanium possesses a number of advantages for MIR applications, such as a wider transparency window (2 - 15 µm), a higher refractive index (~4), and a higher third-order nonlinear susceptibility. Here we present our experimental demonstration of two types of MIR high-Q germanium resonators, namely, a microring resonator and a photonic crystal nanobeam cavity. A maximum Q factor of ~57,000 is experimentally realized, which is the highest to date on germanium platforms. Moreover, we demonstrate a monolithic integration of the high-Q germanium resonators with suspended-membrane waveguides and focusing subwavelength grating couplers. Our resonators pave a new avenue for the study of on-chip light-germanium interactions and development of on-chip MIR applications in sensing and spectroscopy.","PeriodicalId":21725,"journal":{"name":"Silicon Photonics XIV","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82631496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Littlejohns, Ying Tran, H. Du, S. Stankovic, Xingzhao Yan, G. Sharp, M. Sorel, R. Webb, Jonathon England, H. Chong, F. Gardes, D. Thomson, G. Mashanovich, G. Reed
The field of silicon photonics has expanded rapidly over the past several decades. This has led to a degree of standardisation in the commercial device fabrication foundries that are available for universities and fabless companies alike. Whilst this is advantageous in terms of yield, repeatability etc., it is not conducive for researchers to develop new and novel devices for future systems. CORNERSTONE offers researchers a flexible device prototyping capability that can support photonics research around the world. The CORNERSTONE project (Capability for OptoelectRoNics, mEtamateRialS, nanoTechnOlogy, aNd sEnsing) is a UK Engineering and Physical Sciences Research Council (EPSRC) funded project between 3 UK universities: University of Southampton, University of Glasgow and University of Surrey. The project is based on deep-ultraviolet (DUV) photolithography equipment, installed at the University of Southampton, centred around a 248 nm Scanner, the first of its kind in a UK university. Utilising these facilities, CORNERSTONE will offer a multi-project wafer (MPW) service on several silicon-on-insulator (SOI) platforms (220 nm, 340 nm & 500 nm) for both passive and active silicon photonic devices. This talk will give an overview of the CORNERSTONE project, present some of its early data, and summarise future MPW offerings.
{"title":"Rapid device prototyping using the CORNERSTONE platform (Conference Presentation)","authors":"C. Littlejohns, Ying Tran, H. Du, S. Stankovic, Xingzhao Yan, G. Sharp, M. Sorel, R. Webb, Jonathon England, H. Chong, F. Gardes, D. Thomson, G. Mashanovich, G. Reed","doi":"10.1117/12.2508850","DOIUrl":"https://doi.org/10.1117/12.2508850","url":null,"abstract":"The field of silicon photonics has expanded rapidly over the past several decades. This has led to a degree of standardisation in the commercial device fabrication foundries that are available for universities and fabless companies alike. Whilst this is advantageous in terms of yield, repeatability etc., it is not conducive for researchers to develop new and novel devices for future systems. CORNERSTONE offers researchers a flexible device prototyping capability that can support photonics research around the world.\u0000The CORNERSTONE project (Capability for OptoelectRoNics, mEtamateRialS, nanoTechnOlogy, aNd sEnsing) is a UK Engineering and Physical Sciences Research Council (EPSRC) funded project between 3 UK universities: University of Southampton, University of Glasgow and University of Surrey. The project is based on deep-ultraviolet (DUV) photolithography equipment, installed at the University of Southampton, centred around a 248 nm Scanner, the first of its kind in a UK university. Utilising these facilities, CORNERSTONE will offer a multi-project wafer (MPW) service on several silicon-on-insulator (SOI) platforms (220 nm, 340 nm & 500 nm) for both passive and active silicon photonic devices.\u0000This talk will give an overview of the CORNERSTONE project, present some of its early data, and summarise future MPW offerings.","PeriodicalId":21725,"journal":{"name":"Silicon Photonics XIV","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85048976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. A. Pilon, A. Lyasota, V. Reboud, V. Calvo, N. Pauc, J. Widiez, J. Hartmann, A. Chelnokov, J. Faist, H. Sigg
Germanium (Ge), thanks to its CMOS compatibility and near direct bandgap configuration -140 meV offset between the conduction band states at Gamma and L - has been for long in the race for an all-group-IV laser solution. In the GeSn alloy system, such demonstration has been achieved recently [1]. For Ge, the evidences were much less apparent, in spite of the fact that by applying strain [2], a true direct bandgap configuration is expected and thus the prospect for lasing operation is valid. Here, we explored for the first time the regime where (i) we excite the strained micro bridges at an energy much below the Ge bandgap to reduce the optical loss for modes propagating in the unstrained region of the cavity, (ii) the excitation pulse is 100 ps long, a time shorter than the carrier lifetime of > 5 ns and also shorter than the thermal constant of the suspended bridges but (iii) longer than any thermalization and carrier equilibration times. Under these conditions, using uniaxial loading of strain in the range of 5 %, we obtain unambiguous lasing operation near 3.65 µm at low temperatures with linewidths down to 50 GHz with (a) thresholds at carrier concentration of typically 1E18 cm-3, (b) several orders of magnitude raise of the emission efficiency under lasing and (c) spectrally single mode operation, confirming the expected mode/gain competition behaviour. [1] S. Wirths, R. Geiger, et al. NP 2015;9(2):88-92. [2] M.J. Suess, R. Geiger, et al. NP 2013;7(6):466-472.
{"title":"Single-mode lasing in strained Ge microbridges (Conference Presentation)","authors":"F. A. Pilon, A. Lyasota, V. Reboud, V. Calvo, N. Pauc, J. Widiez, J. Hartmann, A. Chelnokov, J. Faist, H. Sigg","doi":"10.1117/12.2510180","DOIUrl":"https://doi.org/10.1117/12.2510180","url":null,"abstract":"Germanium (Ge), thanks to its CMOS compatibility and near direct bandgap configuration -140 meV offset between the conduction band states at Gamma and L - has been for long in the race for an all-group-IV laser solution. In the GeSn alloy system, such demonstration has been achieved recently [1]. For Ge, the evidences were much less apparent, in spite of the fact that by applying strain [2], a true direct bandgap configuration is expected and thus the prospect for lasing operation is valid. Here, we explored for the first time the regime where (i) we excite the strained micro bridges at an energy much below the Ge bandgap to reduce the optical loss for modes propagating in the unstrained region of the cavity, (ii) the excitation pulse is 100 ps long, a time shorter than the carrier lifetime of > 5 ns and also shorter than the thermal constant of the suspended bridges but (iii) longer than any thermalization and carrier equilibration times. Under these conditions, using uniaxial loading of strain in the range of 5 %, we obtain unambiguous lasing operation near 3.65 µm at low temperatures with linewidths down to 50 GHz with (a) thresholds at carrier concentration of typically 1E18 cm-3, (b) several orders of magnitude raise of the emission efficiency under lasing and (c) spectrally single mode operation, confirming the expected mode/gain competition behaviour. \u0000[1] S. Wirths, R. Geiger, et al. NP 2015;9(2):88-92.\u0000[2] M.J. Suess, R. Geiger, et al. NP 2013;7(6):466-472.","PeriodicalId":21725,"journal":{"name":"Silicon Photonics XIV","volume":"123 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85669615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Buca, D. Gruetzmacher, M. E. Kurdi, D. Stange, Z. Ikonić, N. V. D. Driesch, D. Rainko, H. Sigg, J. Hartmann
GeSn is discussed as solution to realize the dream of a group IV light source integrated on a Si chip. Sn added into a Ge lattice decreases the conduction band energies leading to a direct bandgap semiconductor band structure. However, the compressive strain increases the direct band energy imposing a large Sn content in the GeSn bulk. In spite of many difficulties regarding the growth of epitaxial GeSn alloys on Si, several hundred nm thick GeSn layers with various Sn concentrations up to 15% could be realized and used as gain material for lasers. Nowadays research concentrates on increasing the Sn content towards 20 at% as well as structural layout. The challenge here is the decreasing quality at high Sn contents and the isolation of the active layer from the mists formed at the interface with Ge/Si which increase the laser threshold. In this direction we discuss the influence on lasing and threshold of MQW SiGeSn/GeSn heterostructures with different quantum well thicknesses. Other solution proposed is the change of intrinsic strain type from compressive into tensile by introducing Si3N4 stressors and also GeSn on Insulator technology. These methods are well known in CMOS technology and can be applied to very low Sn content GeSn alloys. The discussion on the best way to reach room temperature laser is addressed both theoretical and experimental.
{"title":"Strain engineering in SiGeSn/GeSn heterostructures for light emitters (Conference Presentation)","authors":"D. Buca, D. Gruetzmacher, M. E. Kurdi, D. Stange, Z. Ikonić, N. V. D. Driesch, D. Rainko, H. Sigg, J. Hartmann","doi":"10.1117/12.2511367","DOIUrl":"https://doi.org/10.1117/12.2511367","url":null,"abstract":"GeSn is discussed as solution to realize the dream of a group IV light source integrated on a Si chip. Sn added into a Ge lattice decreases the conduction band energies leading to a direct bandgap semiconductor band structure. However, the compressive strain increases the direct band energy imposing a large Sn content in the GeSn bulk. In spite of many difficulties regarding the growth of epitaxial GeSn alloys on Si, several hundred nm thick GeSn layers with various Sn concentrations up to 15% could be realized and used as gain material for lasers. Nowadays research concentrates on increasing the Sn content towards 20 at% as well as structural layout. The challenge here is the decreasing quality at high Sn contents and the isolation of the active layer from the mists formed at the interface with Ge/Si which increase the laser threshold. In this direction we discuss the influence on lasing and threshold of MQW SiGeSn/GeSn heterostructures with different quantum well thicknesses. Other solution proposed is the change of intrinsic strain type from compressive into tensile by introducing Si3N4 stressors and also GeSn on Insulator technology. These methods are well known in CMOS technology and can be applied to very low Sn content GeSn alloys. The discussion on the best way to reach room temperature laser is addressed both theoretical and experimental.","PeriodicalId":21725,"journal":{"name":"Silicon Photonics XIV","volume":"84 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83066945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Youngkwan Jo, B. Yu, S. Lischke, C. Mai, L. Zimmermann, W. Choi
The depletion-type Si ring modulator (RM) is of great interest among many Si photonic devices for optical interconnect applications because it has a small size, low power consumption, and large modulation bandwidth. Although the major application of the Si RM are digital optical interconnect systems, there is another application of importance, namely microwave photonics in which the modulation linearity is a key performance parameter. We investigate the modulation linearity performance in terms of spurious-free dynamic range (SFDR) of a RM device fabricated by IHP Si PIC foundry. The device has 8-um radius, 290-nm coupling gap and the nominal peak doping concentration of 7×1017 cm−3 for p-region and 3×1018 cm−3 for n-region. The measured SFDR is 78.7 dB·Hz2/3. The major sources of non-linearity of this device are the nonlinear free-carrier plasma dispersion effect in PN junction as well as the nonlinear resonance characteristics. We also perform the numerical simulation of RM SFDR using key device parameters extracted from measurement. The simulation results match well with the measurement results. With this numerical model, we are able to identify the exact cause of RM nonlinearity and come up with suggestions for improving RM linearity.
{"title":"Modulation linearity analysis of depletion-type Si ring modulator (Conference Presentation)","authors":"Youngkwan Jo, B. Yu, S. Lischke, C. Mai, L. Zimmermann, W. Choi","doi":"10.1117/12.2509215","DOIUrl":"https://doi.org/10.1117/12.2509215","url":null,"abstract":"The depletion-type Si ring modulator (RM) is of great interest among many Si photonic devices for optical interconnect applications because it has a small size, low power consumption, and large modulation bandwidth. Although the major application of the Si RM are digital optical interconnect systems, there is another application of importance, namely microwave photonics in which the modulation linearity is a key performance parameter. We investigate the modulation linearity performance in terms of spurious-free dynamic range (SFDR) of a RM device fabricated by IHP Si PIC foundry. The device has 8-um radius, 290-nm coupling gap and the nominal peak doping concentration of 7×1017 cm−3 for p-region and 3×1018 cm−3 for n-region. The measured SFDR is 78.7 dB·Hz2/3. The major sources of non-linearity of this device are the nonlinear free-carrier plasma dispersion effect in PN junction as well as the nonlinear resonance characteristics. We also perform the numerical simulation of RM SFDR using key device parameters extracted from measurement. The simulation results match well with the measurement results. With this numerical model, we are able to identify the exact cause of RM nonlinearity and come up with suggestions for improving RM linearity.","PeriodicalId":21725,"journal":{"name":"Silicon Photonics XIV","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81478978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. L. Tsui, Osamah Alsalman, A. Alodhayb, H. Albrithen, D. Hagan, A. Knights, M. Halsall, I. Crowe
Silicon photonics micro-ring resonator (MRR) and Mach-Zehnder waveguide based sensors have attracted much attention in recent years because of their capacity for high sensitivity, small footprint and mass-scalable (low cost) potential. This type of sensor is based on the detection of changes in optical amplitude/phase due to small changes in local, near-field refractive index (RI) in the environment surrounding the waveguide device. Sensitivity to ever smaller changes in RI are sought, e.g. for vapour/gas based sensing, which may be realised by designing devices based around the slot waveguide. Furthermore, tailoring resonant line-shapes to generate asymmetric (or Fano-like) modes through series, parallel or ‘nested’ arrangements of coupled MRRs also demonstrates the potential for such sensitivity enhancement. This type of device is likely to be of interest, for example where sensing of volatile organic compounds (VOCs) is important, e.g. in industrial process and environmental monitoring. We demonstrate a number of such photonic sensing platforms, combining both the slot waveguide and both established and novel ‘photonic molecule’ structures, fabricated on silicon-on-insulator using standard foundry fabrication processes. Integrated TiN heaters provide the capacity for thermal tuning in order to manipulate the spectral characteristics of our devices and the sensitivity of the devices to a range of VOCs; benzene, toluene and xylene, are investigated as exemplars using a custom-made vapour delivery system. Sensor performance is established with the assistance of device modelling and comparison made with conventional single MRR devices as a reference. The potential of adding functional layers to the devices as a method for achieving chemical selectivity will also be discussed.
{"title":"Silicon 'photonic molecules' for sensing applications (Conference Presentation)","authors":"H. L. Tsui, Osamah Alsalman, A. Alodhayb, H. Albrithen, D. Hagan, A. Knights, M. Halsall, I. Crowe","doi":"10.1117/12.2509919","DOIUrl":"https://doi.org/10.1117/12.2509919","url":null,"abstract":"Silicon photonics micro-ring resonator (MRR) and Mach-Zehnder waveguide based sensors have attracted much attention in recent years because of their capacity for high sensitivity, small footprint and mass-scalable (low cost) potential. This type of sensor is based on the detection of changes in optical amplitude/phase due to small changes in local, near-field refractive index (RI) in the environment surrounding the waveguide device. Sensitivity to ever smaller changes in RI are sought, e.g. for vapour/gas based sensing, which may be realised by designing devices based around the slot waveguide. Furthermore, tailoring resonant line-shapes to generate asymmetric (or Fano-like) modes through series, parallel or ‘nested’ arrangements of coupled MRRs also demonstrates the potential for such sensitivity enhancement. This type of device is likely to be of interest, for example where sensing of volatile organic compounds (VOCs) is important, e.g. in industrial process and environmental monitoring.\u0000\u0000We demonstrate a number of such photonic sensing platforms, combining both the slot waveguide and both established and novel ‘photonic molecule’ structures, fabricated on silicon-on-insulator using standard foundry fabrication processes. Integrated TiN heaters provide the capacity for thermal tuning in order to manipulate the spectral characteristics of our devices and the sensitivity of the devices to a range of VOCs; benzene, toluene and xylene, are investigated as exemplars using a custom-made vapour delivery system. Sensor performance is established with the assistance of device modelling and comparison made with conventional single MRR devices as a reference. The potential of adding functional layers to the devices as a method for achieving chemical selectivity will also be discussed.","PeriodicalId":21725,"journal":{"name":"Silicon Photonics XIV","volume":"89 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75273979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Erbium (Er) has offered a means towards optical amplification around 1.5 µm due to the intra-4f transitions of Er3+ ions. Er silicates are of much interest due to a 3 order increase in the concentration of Er3+ ions in the film as opposed to different Er-doped materials. Unfortunately, the major hindrance toward optical gains in such erbium containing materials is the fast quenching of Er luminescence, mainly resulting from excitation energy dissipation at structural defects even with a small density, via resonant energy transfer processes among Er ions. In this work, we investigate effects of hydrogen passivation and micro/nano scale structures on the luminescence properties of Er silicates. Arrays of micron-sized erbium silicate structures are created via etching a silicon wafer followed by deposition of erbium metal onto the etched pits. After deposition, the photoresist is removed through lift off and the metal structures are subjected to high temperature oxygen annealing (1200˚C) for oxidation of the film. Hydrogen passivation is conducted in a H2 gas ambient between 500˚C and 900˚C. Rutherford backscattering spectroscopy (RBS) and x-ray diffraction (XRD) are used to determine the composition and crystal structure information of the resultant thin films and photoluminescence (PL) is measured for their luminescence properties. The results show a significant decrease of photoluminescence in the ultraviolet/visible (UV/Vis) range, accompanied by an increase in both the intensity and lifetime of the near-infrared (NIR) luminescence emission around 1.5 µm wavelength from Er oxide/silicate compound thin films, following passivation in a H2 gas. Furthermore, samples with arrays of micro-structured Er silicates exhibit stronger NIR luminescence than the thin film sample. Combining with computer simulations, we identify the possible mechanisms for the observed Er luminescence enhancement, and suggest promising routes toward optical amplification around 1.5 µm in Er compounds.
{"title":"Hydrogen passivation and microstructure fabrication in erbium silicates for optical amplification applications around 1.5 um (Conference Presentation)","authors":"D. Vipin, Mengbing Huang","doi":"10.1117/12.2510391","DOIUrl":"https://doi.org/10.1117/12.2510391","url":null,"abstract":"Erbium (Er) has offered a means towards optical amplification around 1.5 µm due to the intra-4f transitions of Er3+ ions. Er silicates are of much interest due to a 3 order increase in the concentration of Er3+ ions in the film as opposed to different Er-doped materials. Unfortunately, the major hindrance toward optical gains in such erbium containing materials is the fast quenching of Er luminescence, mainly resulting from excitation energy dissipation at structural defects even with a small density, via resonant energy transfer processes among Er ions. In this work, we investigate effects of hydrogen passivation and micro/nano scale structures on the luminescence properties of Er silicates. Arrays of micron-sized erbium silicate structures are created via etching a silicon wafer followed by deposition of erbium metal onto the etched pits. After deposition, the photoresist is removed through lift off and the metal structures are subjected to high temperature oxygen annealing (1200˚C) for oxidation of the film. Hydrogen passivation is conducted in a H2 gas ambient between 500˚C and 900˚C. Rutherford backscattering spectroscopy (RBS) and x-ray diffraction (XRD) are used to determine the composition and crystal structure information of the resultant thin films and photoluminescence (PL) is measured for their luminescence properties. The results show a significant decrease of photoluminescence in the ultraviolet/visible (UV/Vis) range, accompanied by an increase in both the intensity and lifetime of the near-infrared (NIR) luminescence emission around 1.5 µm wavelength from Er oxide/silicate compound thin films, following passivation in a H2 gas. Furthermore, samples with arrays of micro-structured Er silicates exhibit stronger NIR luminescence than the thin film sample. Combining with computer simulations, we identify the possible mechanisms for the observed Er luminescence enhancement, and suggest promising routes toward optical amplification around 1.5 µm in Er compounds.","PeriodicalId":21725,"journal":{"name":"Silicon Photonics XIV","volume":"389 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75746233","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
É. Tournié, L. Cerutti, Jean‐baptiste Rodriguez, J. P. Perez, P. Christol, R. Teissier, A. Baranov
{"title":"Antimonide-based optoelectronic devices grown on Si substrates (Conference Presentation)","authors":"É. Tournié, L. Cerutti, Jean‐baptiste Rodriguez, J. P. Perez, P. Christol, R. Teissier, A. Baranov","doi":"10.1117/12.2508158","DOIUrl":"https://doi.org/10.1117/12.2508158","url":null,"abstract":"","PeriodicalId":21725,"journal":{"name":"Silicon Photonics XIV","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76693808","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Monolithic growth of III-V semiconductors on silicon is a promising path for the development of silicon-based lasers. The GaP binary has a lattice constant very close to that of silicon and can be grown defect free without anti-phase domains (APDs) or stacking faults on (001) exact orientated silicon substrates. These GaP on Si templates provide the base for growth and investigation of III-V lasers. The addition of boron can be used to partially replace Ga and further reduce the lattice constant. This can be balanced to match the lattice constant of silicon by adding As to partially replace P. The alloying also provides control of band gaps and band offsets as well as refractive index. The BxGa(1-x)P and BxGa(1-x)AsyP(1-y) alloys are being explored to provide lattice matching/ strain compensation, cladding and the Separate Confined Heterostructure (SCH). The effects of the inclusion of boron on device related alloy properties have not been studied extensively and are not well understood. We investigate the refractive index and extinction coefficient dispersion relation and the electronic band structure properties of these boron containing alloys using spectroscopic ellipsometry to provide inputs for device modelling and optimisation. Results from the spectroscopic ellipsometry are presented for a series of BGaP and BGaAsP alloy samples with boron fractions in the range 0-6.6% and arsenic fractions from 0-17% on GaP substrates and GaP/ Si templates. These results provide important information for the design of lasers with strong optical and electronic confinement, as shall be discussed.
{"title":"BGa(As)P alloys for III-V integration on silicon (Conference Presentation)","authors":"C. R. Fitch, P. Ludewig, W. Stolz, S. Sweeney","doi":"10.1117/12.2506106","DOIUrl":"https://doi.org/10.1117/12.2506106","url":null,"abstract":"Monolithic growth of III-V semiconductors on silicon is a promising path for the development of silicon-based lasers. The GaP binary has a lattice constant very close to that of silicon and can be grown defect free without anti-phase domains (APDs) or stacking faults on (001) exact orientated silicon substrates. These GaP on Si templates provide the base for growth and investigation of III-V lasers. The addition of boron can be used to partially replace Ga and further reduce the lattice constant. This can be balanced to match the lattice constant of silicon by adding As to partially replace P. The alloying also provides control of band gaps and band offsets as well as refractive index. The BxGa(1-x)P and BxGa(1-x)AsyP(1-y) alloys are being explored to provide lattice matching/ strain compensation, cladding and the Separate Confined Heterostructure (SCH). The effects of the inclusion of boron on device related alloy properties have not been studied extensively and are not well understood. We investigate the refractive index and extinction coefficient dispersion relation and the electronic band structure properties of these boron containing alloys using spectroscopic ellipsometry to provide inputs for device modelling and optimisation. Results from the spectroscopic ellipsometry are presented for a series of BGaP and BGaAsP alloy samples with boron fractions in the range 0-6.6% and arsenic fractions from 0-17% on GaP substrates and GaP/ Si templates. These results provide important information for the design of lasers with strong optical and electronic confinement, as shall be discussed.","PeriodicalId":21725,"journal":{"name":"Silicon Photonics XIV","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91012232","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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