A polarization-insensitive thermo-optic switch is proposed and demonstrated on the silicon-on-insulator platform with a 220 nm silicon core layer. The present device is based on the Mach–Zehnder interferometer structure, consisting of polarization-insensitive power splitters and polarization-insensitive phase shifters (PIPSs). The polarization-insensitive power splitter has been realized by employing an adiabatic directional coupler, which utilizes the fast adiabatic mode evolution by introducing cubic Bézier curves on outer contours, providing broadband 3-dB power splitting for TE and TM polarization modes with only 70 µm coupling length. For the novel PIPSs, the ridge waveguide with large aspect ratio, based on the mode hybridness property, could obtain the same power consumption (Pπ) for an optical switch working at TE and TM polarizations. Experimental results indicate that the measured insertion losses are less than 2 dB and the extinction ratios are larger than 15 dB over a 40 nm wavelength band (covering the C-band).
{"title":"Polarization-insensitive silicon optic switch based on mode manipulated power splitters and phase shifters","authors":"Shi Zhao, Jingye Chen, Daoxin Dai, Yaocheng Shi","doi":"10.1063/5.0168090","DOIUrl":"https://doi.org/10.1063/5.0168090","url":null,"abstract":"A polarization-insensitive thermo-optic switch is proposed and demonstrated on the silicon-on-insulator platform with a 220 nm silicon core layer. The present device is based on the Mach–Zehnder interferometer structure, consisting of polarization-insensitive power splitters and polarization-insensitive phase shifters (PIPSs). The polarization-insensitive power splitter has been realized by employing an adiabatic directional coupler, which utilizes the fast adiabatic mode evolution by introducing cubic Bézier curves on outer contours, providing broadband 3-dB power splitting for TE and TM polarization modes with only 70 µm coupling length. For the novel PIPSs, the ridge waveguide with large aspect ratio, based on the mode hybridness property, could obtain the same power consumption (Pπ) for an optical switch working at TE and TM polarizations. Experimental results indicate that the measured insertion losses are less than 2 dB and the extinction ratios are larger than 15 dB over a 40 nm wavelength band (covering the C-band).","PeriodicalId":8198,"journal":{"name":"APL Photonics","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135715554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carlo Silvestri, Xiaoqiong Qi, Thomas Taimre, Aleksandar D. Rakić
This study investigates the interaction between frequency combs and optical feedback effects in Quantum Cascade Lasers (QCLs). The theoretical analysis reveals new phenomena arising from the interplay between comb generation and feedback. By considering the bias current corresponding to free-running single mode emission, the introduction of optical feedback can trigger the generation of frequency combs, including both fundamental and harmonic combs. This presents opportunities to extend the comb region and generate harmonic frequency combs with different orders through optimization of external cavity parameters, such as losses and length. Furthermore, this study demonstrates that optical feedback can selectively tune the harmonic order of a pre-existing free-running comb by adjusting the external cavity length, particularly for feedback ratios around 1%, which are readily achievable in experimental setups. Under strong feedback conditions (Acket parameter C > 4.6), mixed states emerge, displaying the features of both laser and external cavity dynamics. While this study is predominantly centered on terahertz QCLs, we have also confirmed that the described phenomena occur when utilizing mid-infrared QCL parameters. This work establishes a connection between comb technology and the utilization of optical feedback, providing new avenues for exploration and advancement in the field. In fact, the novel reported phenomena open a pathway toward new methodologies across various domains, such as the design of tunable comb sources, hyperspectral imaging, multi-mode coherent sensing, and multi-channel communication.
{"title":"Frequency combs induced by optical feedback and harmonic order tunability in quantum cascade lasers","authors":"Carlo Silvestri, Xiaoqiong Qi, Thomas Taimre, Aleksandar D. Rakić","doi":"10.1063/5.0164597","DOIUrl":"https://doi.org/10.1063/5.0164597","url":null,"abstract":"This study investigates the interaction between frequency combs and optical feedback effects in Quantum Cascade Lasers (QCLs). The theoretical analysis reveals new phenomena arising from the interplay between comb generation and feedback. By considering the bias current corresponding to free-running single mode emission, the introduction of optical feedback can trigger the generation of frequency combs, including both fundamental and harmonic combs. This presents opportunities to extend the comb region and generate harmonic frequency combs with different orders through optimization of external cavity parameters, such as losses and length. Furthermore, this study demonstrates that optical feedback can selectively tune the harmonic order of a pre-existing free-running comb by adjusting the external cavity length, particularly for feedback ratios around 1%, which are readily achievable in experimental setups. Under strong feedback conditions (Acket parameter C > 4.6), mixed states emerge, displaying the features of both laser and external cavity dynamics. While this study is predominantly centered on terahertz QCLs, we have also confirmed that the described phenomena occur when utilizing mid-infrared QCL parameters. This work establishes a connection between comb technology and the utilization of optical feedback, providing new avenues for exploration and advancement in the field. In fact, the novel reported phenomena open a pathway toward new methodologies across various domains, such as the design of tunable comb sources, hyperspectral imaging, multi-mode coherent sensing, and multi-channel communication.","PeriodicalId":8198,"journal":{"name":"APL Photonics","volume":"10 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372011","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We experimentally investigate the properties of crystalline 3D Weaire–Phelan foam structures as photonic crystals. We generate templates on the computer and use direct laser writing (DLW) lithography to fabricate foam designs in a polymer material. Due to the complicated structure of the foams, conventional DLW does not offer the resolution to produce systems with a stop band for telecommunication wavelengths. We employ shrinkage by thermal processing to circumvent this problem and show experimentally that foam Plateau border networks built in this way provide a stop-band within the wavelength interval of λ = 1–2 μm, with the specific wavelength dependent on the degree of shrinkage. We also investigate the dependence of the position and strength of the stop-gap on the solid filling fraction.
{"title":"Experimental realization of Weaire–Phelan foams as photonic crystals","authors":"A. Aguilar Uribe, P. Yazhgur, F. Scheffold","doi":"10.1063/5.0166905","DOIUrl":"https://doi.org/10.1063/5.0166905","url":null,"abstract":"We experimentally investigate the properties of crystalline 3D Weaire–Phelan foam structures as photonic crystals. We generate templates on the computer and use direct laser writing (DLW) lithography to fabricate foam designs in a polymer material. Due to the complicated structure of the foams, conventional DLW does not offer the resolution to produce systems with a stop band for telecommunication wavelengths. We employ shrinkage by thermal processing to circumvent this problem and show experimentally that foam Plateau border networks built in this way provide a stop-band within the wavelength interval of λ = 1–2 μm, with the specific wavelength dependent on the degree of shrinkage. We also investigate the dependence of the position and strength of the stop-gap on the solid filling fraction.","PeriodicalId":8198,"journal":{"name":"APL Photonics","volume":"16 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135410472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dmitrii Konnov, Andrey Muraviev, Sergey Vasilyev, Konstantin Vodopyanov
Ultrabroadband electro-optic sampling using few-optical-cycle probing pulses is a sensitive technique to detect electric field amplitudes with a high dynamic range and up to near-infrared optical frequencies. By combining this method with dual-frequency-comb spectroscopy and using a new class of ultrafast lasers, we perform high-resolution, 80 MHz/0.0027 cm−1 (10 MHz/0.0003 cm−1 with spectral interleaving), spectroscopic measurements in the frequency range 1.5–45 THz (6.6–200 µm), excluding the strongly absorbing Reststrahlen band of lattice resonances at 4.5–9 THz, with an instantaneous spectral coverage exceeding an octave (e.g., 9–22 μm). As a driving source, we use a pair of mutually coherent combs from Kerr-lens mode-locked solid-state Cr:ZnS (2.35 μm) lasers. One of the combs is frequency downconverted via intrapulse difference frequency generation to produce a longwave “sensing” comb, while the second comb is frequency doubled to produce a near-IR “probe” comb for electro-optic sampling (EOS). The low intensity and phase noise of our dual-comb system allow for capturing a large amount of spectral information (200 000 comb-mode-resolved spectral lines spaced by 80 MHz) in the mid-IR portion of the spectrum at a video rate of 69 Hz, with the signal-to-noise ratio limited by the shot noise of the near-IR EOS balanced detection system. Our dual-comb spectroscopy measurements with low-pressure gaseous ethanol, isoprene, and dimethyl sulfide reveal Doppler-limited spectroscopic signatures that have never been explored before.
采用少光周期探测脉冲的超宽带电光采样是一种检测高动态范围、近红外光频率电场幅值的灵敏技术。通过将该方法与双频梳光谱学相结合，并使用一种新型的超快激光器，我们在1.5-45太赫兹(6.6-200 μm)的频率范围内进行了高分辨率，80 MHz/0.0027 cm - 1 (10 MHz/0.0003 cm - 1与光谱交错)的光谱测量，排除了4.5-9太赫兹晶格共振的强吸收Reststrahlen带，瞬时光谱覆盖超过一个倍频程(例如9-22 μm)。我们使用克尔透镜锁模固态Cr:ZnS (2.35 μm)激光器的一对互相干梳作为驱动源。其中一个梳通过脉冲内差频产生频率降频，产生长波“传感”梳，而第二个梳的频率翻倍，产生近红外“探头”梳，用于电光采样(EOS)。我们的双梳系统的低强度和相位噪声允许以69 Hz的视频速率捕获光谱中红外部分的大量光谱信息(20万条梳模式分辨谱线，间隔为80 MHz)，信噪比受到近红外EOS平衡检测系统的散点噪声的限制。我们对低压气体乙醇、异戊二烯和二甲基硫化物的双梳状光谱测量揭示了以前从未探索过的多普勒限制光谱特征。
{"title":"High-resolution frequency-comb spectroscopy with electro-optic sampling and instantaneous octave-wide coverage across mid-IR to THz at a video rate","authors":"Dmitrii Konnov, Andrey Muraviev, Sergey Vasilyev, Konstantin Vodopyanov","doi":"10.1063/5.0165879","DOIUrl":"https://doi.org/10.1063/5.0165879","url":null,"abstract":"Ultrabroadband electro-optic sampling using few-optical-cycle probing pulses is a sensitive technique to detect electric field amplitudes with a high dynamic range and up to near-infrared optical frequencies. By combining this method with dual-frequency-comb spectroscopy and using a new class of ultrafast lasers, we perform high-resolution, 80 MHz/0.0027 cm−1 (10 MHz/0.0003 cm−1 with spectral interleaving), spectroscopic measurements in the frequency range 1.5–45 THz (6.6–200 µm), excluding the strongly absorbing Reststrahlen band of lattice resonances at 4.5–9 THz, with an instantaneous spectral coverage exceeding an octave (e.g., 9–22 μm). As a driving source, we use a pair of mutually coherent combs from Kerr-lens mode-locked solid-state Cr:ZnS (2.35 μm) lasers. One of the combs is frequency downconverted via intrapulse difference frequency generation to produce a longwave “sensing” comb, while the second comb is frequency doubled to produce a near-IR “probe” comb for electro-optic sampling (EOS). The low intensity and phase noise of our dual-comb system allow for capturing a large amount of spectral information (200 000 comb-mode-resolved spectral lines spaced by 80 MHz) in the mid-IR portion of the spectrum at a video rate of 69 Hz, with the signal-to-noise ratio limited by the shot noise of the near-IR EOS balanced detection system. Our dual-comb spectroscopy measurements with low-pressure gaseous ethanol, isoprene, and dimethyl sulfide reveal Doppler-limited spectroscopic signatures that have never been explored before.","PeriodicalId":8198,"journal":{"name":"APL Photonics","volume":"21 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135455896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Charbel Tannoury, Victor Merupo, Giuseppe Di Gioia, Vanessa Avramovic, David Troadec, Jean-François Lampin, Guillaume Ducournau, Steffen Breuer, Björn Globisch, Stefano Barbieri, Robert B. Kohlhaas, Emilien Peytavit
We present an optoelectronic mixer for the terahertz (THz) frequency-domain based on an iron-doped InGaAs layer integrated in a plasmonic microcavity. We show that this structure, under 1550-nm-wavelength illumination, allows for more than 70% absorption efficiency in a 220 nm-thin InGaAs absorber and very high Roff/Ron >1000. It leads to THz mixers driven by 1550-nm lasers showing conversion loss as low as ∼30 dB at 300 GHz. Therefore, this design is very promising for application as receivers in high-data-rate wireless telecom, in cw-THz spectrometers, or in photonics-enabled THz spectrum analyzers.
{"title":"Photonic THz mixers based on iron-doped InGaAs embedded in a plasmonic microcavity","authors":"Charbel Tannoury, Victor Merupo, Giuseppe Di Gioia, Vanessa Avramovic, David Troadec, Jean-François Lampin, Guillaume Ducournau, Steffen Breuer, Björn Globisch, Stefano Barbieri, Robert B. Kohlhaas, Emilien Peytavit","doi":"10.1063/5.0153046","DOIUrl":"https://doi.org/10.1063/5.0153046","url":null,"abstract":"We present an optoelectronic mixer for the terahertz (THz) frequency-domain based on an iron-doped InGaAs layer integrated in a plasmonic microcavity. We show that this structure, under 1550-nm-wavelength illumination, allows for more than 70% absorption efficiency in a 220 nm-thin InGaAs absorber and very high Roff/Ron >1000. It leads to THz mixers driven by 1550-nm lasers showing conversion loss as low as ∼30 dB at 300 GHz. Therefore, this design is very promising for application as receivers in high-data-rate wireless telecom, in cw-THz spectrometers, or in photonics-enabled THz spectrum analyzers.","PeriodicalId":8198,"journal":{"name":"APL Photonics","volume":"26 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135325545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Catalá-Lahoz, D. Pérez-López, T. Huy-Ho, J. Capmany
Reconfigurable photonic filters show great promise as a potential solution to meet the evolving needs of future microwave communication systems. By integrating high-performance filters into programmable microwave photonic processors, they can provide significant benefits for signal processing applications. The development of an algorithm that can automatically characterize and reconfigure the filter using a single optical input and output port is essential for this purpose. This paper presents an optimization technique for a fully tunable ring-assisted Mach–Zehnder interferometer filter. The proposed filter design eliminates the need for monitoring components and employs a novel algorithm that operates independently in each ring by switching between the two arms of the filter. In addition, the filter can be configured to implement different filter architectures, allowing for flexible filtering requirements. Measurements were performed using the device as an interleaver, implementing different types of infinite impulse response filters in the optical and radio frequency domains. Side-coupled integrated spaced sequence of resonator filters were also implemented by reconfiguring the same device. These results demonstrate the exceptional reconfigurability of the filter design proposed herein in terms of bandwidth and central frequency.
{"title":"Self-configuring programmable silicon photonic filter for integrated microwave photonic processors","authors":"C. Catalá-Lahoz, D. Pérez-López, T. Huy-Ho, J. Capmany","doi":"10.1063/5.0169544","DOIUrl":"https://doi.org/10.1063/5.0169544","url":null,"abstract":"Reconfigurable photonic filters show great promise as a potential solution to meet the evolving needs of future microwave communication systems. By integrating high-performance filters into programmable microwave photonic processors, they can provide significant benefits for signal processing applications. The development of an algorithm that can automatically characterize and reconfigure the filter using a single optical input and output port is essential for this purpose. This paper presents an optimization technique for a fully tunable ring-assisted Mach–Zehnder interferometer filter. The proposed filter design eliminates the need for monitoring components and employs a novel algorithm that operates independently in each ring by switching between the two arms of the filter. In addition, the filter can be configured to implement different filter architectures, allowing for flexible filtering requirements. Measurements were performed using the device as an interleaver, implementing different types of infinite impulse response filters in the optical and radio frequency domains. Side-coupled integrated spaced sequence of resonator filters were also implemented by reconfiguring the same device. These results demonstrate the exceptional reconfigurability of the filter design proposed herein in terms of bandwidth and central frequency.","PeriodicalId":8198,"journal":{"name":"APL Photonics","volume":"10 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135372010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Haotian Cheng, Naijun Jin, Zhaowei Dai, Chao Xiang, Joel Guo, Yishu Zhou, Scott A. Diddams, Franklyn Quinlan, John Bowers, Owen Miller, Peter Rakich
The unique benefits of Fabry–Pérot resonators as frequency-stable reference cavities and as an efficient interface between atoms and photons make them an indispensable resource for emerging photonic technologies. To bring these performance benefits to next-generation communications, computation, and time-keeping systems, it will be necessary to develop strategies to integrate compact Fabry–Pérot resonators with photonic integrated circuits. In this paper, we demonstrate a novel reflection cancellation circuit that utilizes a numerically optimized multi-port polarization-splitting grating coupler to efficiently interface high-finesse Fabry–Pérot resonators with a silicon photonic circuit. This circuit interface produces a spatial separation of the incident and reflected waves, as required for on-chip Pound–Drever–Hall frequency locking, while also suppressing unwanted back reflections from the Fabry–Pérot resonator. Using inverse design principles, we design and fabricate a polarization-splitting grating coupler that achieves 55% coupling efficiency. This design realizes an insertion loss of 5.8 dB for the circuit interface and more than 9 dB of back reflection suppression, and we demonstrate the versatility of this system by using it to interface several reflective off-chip devices.
{"title":"A novel approach to interface high-Q Fabry–Pérot resonators with photonic circuits","authors":"Haotian Cheng, Naijun Jin, Zhaowei Dai, Chao Xiang, Joel Guo, Yishu Zhou, Scott A. Diddams, Franklyn Quinlan, John Bowers, Owen Miller, Peter Rakich","doi":"10.1063/5.0174384","DOIUrl":"https://doi.org/10.1063/5.0174384","url":null,"abstract":"The unique benefits of Fabry–Pérot resonators as frequency-stable reference cavities and as an efficient interface between atoms and photons make them an indispensable resource for emerging photonic technologies. To bring these performance benefits to next-generation communications, computation, and time-keeping systems, it will be necessary to develop strategies to integrate compact Fabry–Pérot resonators with photonic integrated circuits. In this paper, we demonstrate a novel reflection cancellation circuit that utilizes a numerically optimized multi-port polarization-splitting grating coupler to efficiently interface high-finesse Fabry–Pérot resonators with a silicon photonic circuit. This circuit interface produces a spatial separation of the incident and reflected waves, as required for on-chip Pound–Drever–Hall frequency locking, while also suppressing unwanted back reflections from the Fabry–Pérot resonator. Using inverse design principles, we design and fabricate a polarization-splitting grating coupler that achieves 55% coupling efficiency. This design realizes an insertion loss of 5.8 dB for the circuit interface and more than 9 dB of back reflection suppression, and we demonstrate the versatility of this system by using it to interface several reflective off-chip devices.","PeriodicalId":8198,"journal":{"name":"APL Photonics","volume":"17 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135410470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Benhamou-Bui, C. Consejo, S. S. Krishtopenko, M. Szola, K. Maussang, S. Ruffenach, E. Chauveau, S. Benlemqwanssa, C. Bray, X. Baudry, P. Ballet, S. V. Morozov, V. I. Gavrilenko, N. N. Mikhailov, S. A. Dvoretskii, B. Jouault, J. Torres, F. Teppe
Two-dimensional Dirac fermions in HgTe quantum wells close to the topological phase transition can generate significant cyclotron emission that is magnetic field tunable in the terahertz frequency range. Due to their relativistic-like dynamics, their cyclotron mass is strongly dependent on their electron concentration in the quantum well, providing a second tunability lever and paving the way for a gate-tunable, permanent-magnet Landau laser. In this work, we demonstrate the proof-of-concept of such a back-gate tunable THz cyclotron emitter at a fixed magnetic field. The emission frequency detected at 1.5 T is centered at 2.2 THz and can already be electrically tuned over 250 GHz. With an optimized gate and a realistic permanent magnet of 1.0 T, we estimate that the cyclotron emission could be continuously and rapidly tunable by the gate bias between 1 and 3 THz, that is to say on the less covered part of the THz gap.
{"title":"Gate tunable terahertz cyclotron emission from two-dimensional Dirac fermions","authors":"B. Benhamou-Bui, C. Consejo, S. S. Krishtopenko, M. Szola, K. Maussang, S. Ruffenach, E. Chauveau, S. Benlemqwanssa, C. Bray, X. Baudry, P. Ballet, S. V. Morozov, V. I. Gavrilenko, N. N. Mikhailov, S. A. Dvoretskii, B. Jouault, J. Torres, F. Teppe","doi":"10.1063/5.0168578","DOIUrl":"https://doi.org/10.1063/5.0168578","url":null,"abstract":"Two-dimensional Dirac fermions in HgTe quantum wells close to the topological phase transition can generate significant cyclotron emission that is magnetic field tunable in the terahertz frequency range. Due to their relativistic-like dynamics, their cyclotron mass is strongly dependent on their electron concentration in the quantum well, providing a second tunability lever and paving the way for a gate-tunable, permanent-magnet Landau laser. In this work, we demonstrate the proof-of-concept of such a back-gate tunable THz cyclotron emitter at a fixed magnetic field. The emission frequency detected at 1.5 T is centered at 2.2 THz and can already be electrically tuned over 250 GHz. With an optimized gate and a realistic permanent magnet of 1.0 T, we estimate that the cyclotron emission could be continuously and rapidly tunable by the gate bias between 1 and 3 THz, that is to say on the less covered part of the THz gap.","PeriodicalId":8198,"journal":{"name":"APL Photonics","volume":"22 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135510563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andreas Messner, David Moor, Daniel Chelladurai, Roman Svoboda, Jasmin Smajic, Juerg Leuthold
Electro-optic modulators are key elements in high-speed optical telecommunication links and preferably rely on materials with a linear electro-optic effect. Choosing adequate waveguide geometries is a key challenge in the design of electro-optic modulators. While all-dielectric geometries promise high-speed modulation with low propagation loss, their modulation efficiency suffers from low confinement and weak electrical fields, resulting in lengthy devices. Plasmonic geometries, on the other hand, allow for most compact devices featuring highest electro-optical bandwidths, but at the cost of higher losses. Alternatively, hybrid photonic–plasmonic solutions open a sweet spot for high-speed modulators with moderate loss. In this review, we discuss the three waveguide types by analyzing and comparing their performance and their sensitivity to variations in geometry with respect to a choice of the electro-optical Pockels-effect material.
{"title":"Plasmonic, photonic, or hybrid? Reviewing waveguide geometries for electro-optic modulators","authors":"Andreas Messner, David Moor, Daniel Chelladurai, Roman Svoboda, Jasmin Smajic, Juerg Leuthold","doi":"10.1063/5.0159166","DOIUrl":"https://doi.org/10.1063/5.0159166","url":null,"abstract":"Electro-optic modulators are key elements in high-speed optical telecommunication links and preferably rely on materials with a linear electro-optic effect. Choosing adequate waveguide geometries is a key challenge in the design of electro-optic modulators. While all-dielectric geometries promise high-speed modulation with low propagation loss, their modulation efficiency suffers from low confinement and weak electrical fields, resulting in lengthy devices. Plasmonic geometries, on the other hand, allow for most compact devices featuring highest electro-optical bandwidths, but at the cost of higher losses. Alternatively, hybrid photonic–plasmonic solutions open a sweet spot for high-speed modulators with moderate loss. In this review, we discuss the three waveguide types by analyzing and comparing their performance and their sensitivity to variations in geometry with respect to a choice of the electro-optical Pockels-effect material.","PeriodicalId":8198,"journal":{"name":"APL Photonics","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135457070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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