S. Chuang, D. Schoellner, A. Ugolini, J. Wakjira, G. Wolf
As parallel optics applications continue to expand, there remains a need for an effective coupling interface between the board-level active components and the passive components of the network. While mid-board level photonic turn connectors are available, coupling interfaces are generally not available outside of proprietary solutions. Development of a general mechanical-optical coupling interface opens the door for broader parallel optics implementation. An interface for use between the optical transmitter and the photonic turn connector is introduced. The interface is a monolithic injection molded component with an array of collimating lenses to couple efficiently with common VCSEL/PD designs. The component has precise epoxy control features to manage epoxy bond-line thickness and strength. Suitable UV and thermal epoxies have been qualified for effective die bond placement of the component in the VCSEL/PD environment. Environmental and mechanical performance of the component to industry-standard qualification requirements are reviewed, and tensile force testing and durability results validate the mechanical characteristics of the interface.
{"title":"Development and qualification of a mechanical-optical interface for parallel optics links","authors":"S. Chuang, D. Schoellner, A. Ugolini, J. Wakjira, G. Wolf","doi":"10.1117/12.2077597","DOIUrl":"https://doi.org/10.1117/12.2077597","url":null,"abstract":"As parallel optics applications continue to expand, there remains a need for an effective coupling interface between the board-level active components and the passive components of the network. While mid-board level photonic turn connectors are available, coupling interfaces are generally not available outside of proprietary solutions. Development of a general mechanical-optical coupling interface opens the door for broader parallel optics implementation. An interface for use between the optical transmitter and the photonic turn connector is introduced. The interface is a monolithic injection molded component with an array of collimating lenses to couple efficiently with common VCSEL/PD designs. The component has precise epoxy control features to manage epoxy bond-line thickness and strength. Suitable UV and thermal epoxies have been qualified for effective die bond placement of the component in the VCSEL/PD environment. Environmental and mechanical performance of the component to industry-standard qualification requirements are reviewed, and tensile force testing and durability results validate the mechanical characteristics of the interface.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114718005","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}
T. Aalto, M. Harjanne, S. Ylinen, M. Kapulainen, T. Vehmas, M. Cherchi, C. Neumeyr, M. Ortsiefer, A. Malacarne
We present a vision for transceiver integration on a 3 μm SOI waveguide platform for systems scalable to Pb/s. We also present experimental results from the first building blocks developed in the EU-funded RAPIDO project. At 1.3 μm wavelength 80 Gb/s per wavelength is to be achieved using hybrid integration of III-V optoelectronics on SOI. Goals include athermal operation, low-loss I/O coupling, advanced modulation formats and packet switching. An example of the design results is an interposer chip that consists of 12 μm thick SOI waveguides locally tapered down to 3 μm to provide low-loss coupling between an optical single-mode fiber array and the 3 μm SOI chip. First example of experimental results is a 4x4 cyclic AWGs with 5 nm channel spacing, 0.4 dB/facet fiber coupling loss, 3.5 dB center-tocenter loss, and -23 dB adjacent channel crosstalk in 3.5x1.5 mm2 footprint. The second example result is a new VCSEL design that was demonstrated to have up to 40 Gb/s operation at 1.55 μm.
{"title":"Multi-wavelength transceiver integration on SOI for high-performance computing system applications","authors":"T. Aalto, M. Harjanne, S. Ylinen, M. Kapulainen, T. Vehmas, M. Cherchi, C. Neumeyr, M. Ortsiefer, A. Malacarne","doi":"10.1117/12.2079682","DOIUrl":"https://doi.org/10.1117/12.2079682","url":null,"abstract":"We present a vision for transceiver integration on a 3 μm SOI waveguide platform for systems scalable to Pb/s. We also present experimental results from the first building blocks developed in the EU-funded RAPIDO project. At 1.3 μm wavelength 80 Gb/s per wavelength is to be achieved using hybrid integration of III-V optoelectronics on SOI. Goals include athermal operation, low-loss I/O coupling, advanced modulation formats and packet switching. An example of the design results is an interposer chip that consists of 12 μm thick SOI waveguides locally tapered down to 3 μm to provide low-loss coupling between an optical single-mode fiber array and the 3 μm SOI chip. First example of experimental results is a 4x4 cyclic AWGs with 5 nm channel spacing, 0.4 dB/facet fiber coupling loss, 3.5 dB center-tocenter loss, and -23 dB adjacent channel crosstalk in 3.5x1.5 mm2 footprint. The second example result is a new VCSEL design that was demonstrated to have up to 40 Gb/s operation at 1.55 μm.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116011766","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}
Ki-seok Jang, Jiho Joo, Taeyong Kim, Sanghoon Kim, J. Oh, I. Kim, Sun Ae Kim, Gyungock Kim
We report a 40 Gb/s photoreceiver based on vertical-illumination type Ge-on-Si photodetectors and a silica-based AWG demultiplexer by employing 4-channel CWDM. The 60um-diameter Ge-on-Si photodetector arrays, grown on a bulk silicon wafer by RPCVD and fabricated with CMOS-compatible process, have ~0.9 A/W responsivity with 13 GHz bandwidth at λ ~ 1330nm. Ge-on-Si photodetector arrays are hybrid-integrated with TIA/LAs and directly-coupled to the AWG. The low-cost FPCB-package based photoreceiver module shows 10.3 Gb/s × 4-channel interconnection with -11 ~ -12.2 dBm sensitivity at a BER = 10-12.
{"title":"A CWDM photoreceiver module for 10 Gb/s x 4ch interconnection based on a vertical-illumination-type Ge-on-Si photodetectors and a silica-based AWG","authors":"Ki-seok Jang, Jiho Joo, Taeyong Kim, Sanghoon Kim, J. Oh, I. Kim, Sun Ae Kim, Gyungock Kim","doi":"10.1117/12.2078844","DOIUrl":"https://doi.org/10.1117/12.2078844","url":null,"abstract":"We report a 40 Gb/s photoreceiver based on vertical-illumination type Ge-on-Si photodetectors and a silica-based AWG demultiplexer by employing 4-channel CWDM. The 60um-diameter Ge-on-Si photodetector arrays, grown on a bulk silicon wafer by RPCVD and fabricated with CMOS-compatible process, have ~0.9 A/W responsivity with 13 GHz bandwidth at λ ~ 1330nm. Ge-on-Si photodetector arrays are hybrid-integrated with TIA/LAs and directly-coupled to the AWG. The low-cost FPCB-package based photoreceiver module shows 10.3 Gb/s × 4-channel interconnection with -11 ~ -12.2 dBm sensitivity at a BER = 10-12.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121735165","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}
J. Müller, J. Hauck, B. Shen, S. Romero-García, E. Islamova, S. Sharif Azadeh, S. Joshi, N. Chimot, A. Moscoso-Mártir, F. Merget, F. Lelarge, J. Witzens
We demonstrate wavelength domain multiplexed (WDM) data transmission with a data rate of 14 Gbps based on optical carrier generation with a single-section semiconductor mode-locked laser (SS-MLL) and modulation with a Silicon Photonics (SiP) resonant ring modulator (RRM). 18 channels are sequentially measured, whereas the best recorded eye diagrams feature signal quality factors (Q-factors) above 7. While optical re-amplification was necessary to maintain the link budgets and therefore system measurements were performed with an erbium doped fiber amplifier (EDFA), preliminary characterization done with a semiconductor optical amplifier (SOA) indicates compatibility with the latter pending the integration of an additional optical filter to select a subset of carriers and prevent SOA saturation. A systematic analysis of the relative intensity noise (RIN) of isolated comb lines and of signal Q-factors indicates that the link is primarily limited by amplified spontaneous emission (ASE) from the EDFA rather than laser RIN. Measured RIN for single comb components is below -120 dBc/Hz in the range from 7 MHz to 4 GHz and drops to the shot noise level at higher frequencies.
{"title":"Silicon photonics WDM interconnects based on resonant ring modulators and semiconductor mode locked laser","authors":"J. Müller, J. Hauck, B. Shen, S. Romero-García, E. Islamova, S. Sharif Azadeh, S. Joshi, N. Chimot, A. Moscoso-Mártir, F. Merget, F. Lelarge, J. Witzens","doi":"10.1117/12.2080769","DOIUrl":"https://doi.org/10.1117/12.2080769","url":null,"abstract":"We demonstrate wavelength domain multiplexed (WDM) data transmission with a data rate of 14 Gbps based on optical carrier generation with a single-section semiconductor mode-locked laser (SS-MLL) and modulation with a Silicon Photonics (SiP) resonant ring modulator (RRM). 18 channels are sequentially measured, whereas the best recorded eye diagrams feature signal quality factors (Q-factors) above 7. While optical re-amplification was necessary to maintain the link budgets and therefore system measurements were performed with an erbium doped fiber amplifier (EDFA), preliminary characterization done with a semiconductor optical amplifier (SOA) indicates compatibility with the latter pending the integration of an additional optical filter to select a subset of carriers and prevent SOA saturation. A systematic analysis of the relative intensity noise (RIN) of isolated comb lines and of signal Q-factors indicates that the link is primarily limited by amplified spontaneous emission (ASE) from the EDFA rather than laser RIN. Measured RIN for single comb components is below -120 dBc/Hz in the range from 7 MHz to 4 GHz and drops to the shot noise level at higher frequencies.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131395793","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}
Po-Kuan Shen, Xiaochuan Xu, A. Hosseini, Zeyu Pan, Ray T. Chen
In on-chip optical interconnect, dielectric waveguide arrays are usually designed with pitches of a few wavelengths to avoid crosstalk, which greatly limits the integration density. In this paper, we for the first time propose to use multipleinput multiple-output (MIMO), a well-known technique in wireless communication, to recover the data from entangled signals and reduce the waveguide pitch to subwavelength range. In the proposed on-chip MIMO system, there is significant coupling among the adjacent waveguides in the high density waveguide region. In order to recover signals, the N×N transmission matrix of N high-density waveguides is calculated to describe the relation between each input ports and output ports. In the receiving part, homodyne coherent receivers are used to receive the transmitted signals, and obtain the signal in phase and /2 out of phase with local oscillator. In the electrical signal processing, the inverse transmission matrix is utilized to recover the signals in the electronic domain. To verify the proposed on-chip MIMO, we used the INTERCONNECT package in Lumerical software to simulate a 10x10 MIMO system. The cross section of each waveguide is 500 nm x 220 nm. The spacing is 250 nm. The simulation verifies the possibility of recovering 10 Gbps data from the heavily coupled 10 waveguides with a BER better than 10−12. The minimum input optical power for a BER of 10−12 is greater than -18.1 dBm, and the maximum phase shift between input laser and local oscillator can reach to 73.5˚.
{"title":"Multiple-input multiple-output based high density on-chip optical interconnect","authors":"Po-Kuan Shen, Xiaochuan Xu, A. Hosseini, Zeyu Pan, Ray T. Chen","doi":"10.1117/12.2080666","DOIUrl":"https://doi.org/10.1117/12.2080666","url":null,"abstract":"In on-chip optical interconnect, dielectric waveguide arrays are usually designed with pitches of a few wavelengths to avoid crosstalk, which greatly limits the integration density. In this paper, we for the first time propose to use multipleinput multiple-output (MIMO), a well-known technique in wireless communication, to recover the data from entangled signals and reduce the waveguide pitch to subwavelength range. In the proposed on-chip MIMO system, there is significant coupling among the adjacent waveguides in the high density waveguide region. In order to recover signals, the N×N transmission matrix of N high-density waveguides is calculated to describe the relation between each input ports and output ports. In the receiving part, homodyne coherent receivers are used to receive the transmitted signals, and obtain the signal in phase and /2 out of phase with local oscillator. In the electrical signal processing, the inverse transmission matrix is utilized to recover the signals in the electronic domain. To verify the proposed on-chip MIMO, we used the INTERCONNECT package in Lumerical software to simulate a 10x10 MIMO system. The cross section of each waveguide is 500 nm x 220 nm. The spacing is 250 nm. The simulation verifies the possibility of recovering 10 Gbps data from the heavily coupled 10 waveguides with a BER better than 10−12. The minimum input optical power for a BER of 10−12 is greater than -18.1 dBm, and the maximum phase shift between input laser and local oscillator can reach to 73.5˚.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"465 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131836963","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}
Femtosecond laser microprocessing is a direct, maskless fabrication technique that has attracted much attention in the past 10 years due to its unprecedented versatility in the 3D patterning of transparent materials. Two common modalities of femtosecond laser microfabrication include buried optical waveguide writing and surface laser ablation, which have been applied to a wide range of transparent substrates including glasses, polymers and crystals. In two photon polymerization, a third modality of femtosecond laser fabrication, focused femtosecond laser pulses drive photopolymerization in photoresists, enabling the writing of complex 3D structures with submicrometer resolution. In this paper, we discuss several microdevices realized by these diverse modalities of femtosecond laser microfabrication, for applications in microfluidics, sensing and quantum information.
{"title":"Femtosecond laser micromachining for the realization of fully integrated photonic and microfluidic devices","authors":"S. Eaton, R. Osellame, R. Ramponi","doi":"10.1117/12.2076983","DOIUrl":"https://doi.org/10.1117/12.2076983","url":null,"abstract":"Femtosecond laser microprocessing is a direct, maskless fabrication technique that has attracted much attention in the past 10 years due to its unprecedented versatility in the 3D patterning of transparent materials. Two common modalities of femtosecond laser microfabrication include buried optical waveguide writing and surface laser ablation, which have been applied to a wide range of transparent substrates including glasses, polymers and crystals. In two photon polymerization, a third modality of femtosecond laser fabrication, focused femtosecond laser pulses drive photopolymerization in photoresists, enabling the writing of complex 3D structures with submicrometer resolution. In this paper, we discuss several microdevices realized by these diverse modalities of femtosecond laser microfabrication, for applications in microfluidics, sensing and quantum information.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127674160","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}
In this work, we present fabrication and measurement results of an As2S3-on-LiNbO3 ring resonator waveguide and sidewall grating cavity waveguide. The nonlinear tuning capability is demonstrated on a fabricated ring resonator waveguide by injecting the signal-pump optical power into the device and observing the nonlinear phase shift. The nonlinear tunability of our hybrid As2S3-on-LiNbO3 grating cavity waveguide is numerically analyzed.
{"title":"Resonant enhanced low-power nonlinear tuning capability using an As2S3 waveguide on LiNbO3","authors":"Yifeng Zhou, Xin Wang, Chen Zhang, C. Madsen","doi":"10.1117/12.2080071","DOIUrl":"https://doi.org/10.1117/12.2080071","url":null,"abstract":"In this work, we present fabrication and measurement results of an As2S3-on-LiNbO3 ring resonator waveguide and sidewall grating cavity waveguide. The nonlinear tuning capability is demonstrated on a fabricated ring resonator waveguide by injecting the signal-pump optical power into the device and observing the nonlinear phase shift. The nonlinear tunability of our hybrid As2S3-on-LiNbO3 grating cavity waveguide is numerically analyzed.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"9365 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130163664","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}
We present a comparison of different silicon photonics-based wavelength filters for different design criteria (e.g. channel spacing, number of channels, ...) and different performance metrics (e.g. insertion loss or crosstalk ). In this paper we compare only non-resonant filters, or finite-impulse response (FIR) filters, such as Arrayed Waveguide Gratings, Echelle Gratings and higher-order cascades of Mach-Zehnder filters. We derive the strengths and weaknesses from their operational principles and confirm those with experimental data from fabricated devices and extrapolated simulations.
{"title":"Silicon photonics non-resonant wavelength filters: comparison between AWGs, echelle gratings, and cascaded Mach-Zehnder filters","authors":"W. Bogaerts, S. Pathak, A. Ruocco, S. Dwivedi","doi":"10.1117/12.2082785","DOIUrl":"https://doi.org/10.1117/12.2082785","url":null,"abstract":"We present a comparison of different silicon photonics-based wavelength filters for different design criteria (e.g. channel spacing, number of channels, ...) and different performance metrics (e.g. insertion loss or crosstalk ). In this paper we compare only non-resonant filters, or finite-impulse response (FIR) filters, such as Arrayed Waveguide Gratings, Echelle Gratings and higher-order cascades of Mach-Zehnder filters. We derive the strengths and weaknesses from their operational principles and confirm those with experimental data from fabricated devices and extrapolated simulations.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129836140","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}
In this work, we present fabrication and measurement of sidewall Bragg gratings in chalcogenide arsenic tri-sulfide (As2S3) on titanium-diffused lithium niobate (Ti:LiNbO3) channel waveguides. The transfer matrix method was used to analyze the temporal and spectral response of the sidewall gratings in the mid-infrared. The waveguide sidewall Bragg gratings were fabricated by electron-beam lithography (EBL), metal liftoff and subsequent reactive-ion etching (RIE). Insertion loss of the mid-infrared Ti:LiNbO3 optical waveguides were measured at ~2 dB and the propagation loss was estimated to be 0.45 dB/cm. Configuration of an optical low-coherence interferometer that is capable of characterizing the mid-infrared sidewall grating-based devices was experimentally implemented and preliminary results from fiber Bragg gratings are presented.
{"title":"Characterization of sidewall Bragg gratings using optical low-coherence interferometry with a broadband source","authors":"Chen Zhang, Xin Wang, C. Madsen","doi":"10.1117/12.2080104","DOIUrl":"https://doi.org/10.1117/12.2080104","url":null,"abstract":"In this work, we present fabrication and measurement of sidewall Bragg gratings in chalcogenide arsenic tri-sulfide (As2S3) on titanium-diffused lithium niobate (Ti:LiNbO3) channel waveguides. The transfer matrix method was used to analyze the temporal and spectral response of the sidewall gratings in the mid-infrared. The waveguide sidewall Bragg gratings were fabricated by electron-beam lithography (EBL), metal liftoff and subsequent reactive-ion etching (RIE). Insertion loss of the mid-infrared Ti:LiNbO3 optical waveguides were measured at ~2 dB and the propagation loss was estimated to be 0.45 dB/cm. Configuration of an optical low-coherence interferometer that is capable of characterizing the mid-infrared sidewall grating-based devices was experimentally implemented and preliminary results from fiber Bragg gratings are presented.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"63 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121125499","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}
Electro-optically induced waveguides can be used in fiber optic networks for optical power control and the distribution of optical signals transmitted over optical fibers. Reliable operation is ensured with this type of waveguides due to their non-mechanical principle of operation. Their polarization dependent behavior caused by field-induced birefringence effects may limit however their practical applications. We report on a method to reduce the polarization dependent loss in electro-optically induced waveguides with a core made of liquid crystals in isotropic phase. The concept design enables a controlled adjustment of the electric field distribution, which is responsible for inducing and shaping the optical mode, by employing an optimized electrode arrangement. In this new waveguide structure, the TM and TE modes coexist spatially and are guided in a similar way. In order to demonstrate this concept, straight and bending waveguides in 1×1 and 1×2 light input to output configurations have been designed and fabricated. The electrode arrangement and single mode waveguide geometry were optimized using FEM simulations. Bulk silicon micromachining was used to fabricate these waveguides. In particular, the manufactured device consisted of two processed silicon substrates with a liquid crystal layer enclosed in between. Devices tested with varying driving voltage have revealed comparable transmitted power for both TE and TM modes. Very low polarization dependent losses over a more than 20 dB wide dynamic attenuation range have been obtained.
{"title":"Polarization independent electro-optical waveguides with liquid crystals in isotropic phase","authors":"F. Costache, Martin Blasl, K. Bornhorst","doi":"10.1117/12.2079209","DOIUrl":"https://doi.org/10.1117/12.2079209","url":null,"abstract":"Electro-optically induced waveguides can be used in fiber optic networks for optical power control and the distribution of optical signals transmitted over optical fibers. Reliable operation is ensured with this type of waveguides due to their non-mechanical principle of operation. Their polarization dependent behavior caused by field-induced birefringence effects may limit however their practical applications. We report on a method to reduce the polarization dependent loss in electro-optically induced waveguides with a core made of liquid crystals in isotropic phase. The concept design enables a controlled adjustment of the electric field distribution, which is responsible for inducing and shaping the optical mode, by employing an optimized electrode arrangement. In this new waveguide structure, the TM and TE modes coexist spatially and are guided in a similar way. In order to demonstrate this concept, straight and bending waveguides in 1×1 and 1×2 light input to output configurations have been designed and fabricated. The electrode arrangement and single mode waveguide geometry were optimized using FEM simulations. Bulk silicon micromachining was used to fabricate these waveguides. In particular, the manufactured device consisted of two processed silicon substrates with a liquid crystal layer enclosed in between. Devices tested with varying driving voltage have revealed comparable transmitted power for both TE and TM modes. Very low polarization dependent losses over a more than 20 dB wide dynamic attenuation range have been obtained.","PeriodicalId":432115,"journal":{"name":"Photonics West - Optoelectronic Materials and Devices","volume":"1819 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129754014","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}