The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Ai Qun Liu - One of the best experts on this subject based on the ideXlab platform.
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Coupled-ring reflector in an External-Cavity tunable laser
Optica, 2015Co-Authors: M. Ren, Hong Cai, Lip Ket Chin, K. Radhakrishnan, Dim-lee Kwong, Ai Qun LiuAbstract:Miniaturized tunable lasers are important as light sources in optical networks and sensing systems. However, challenges remain in realizing a low-cost on-chip tunable laser with high tuning accuracy and wide tuning range. Here, an External-Cavity tunable laser integrated by using a pair of coupled-ring resonators as a reflector onto a single silicon chip is designed and demonstrated. The silicon coupled-ring reflector provides simultaneous tuning of the central reflective wavelength and the free spectral range of the entire Cavity to guarantee phase matching. The effective optical length of the coupled-ring reflector is controlled by the complementary thermo-optic and free-carrier dispersion effects, thus enabling high-resolution wavelength fine-tuning while maintaining wide wavelength tuning range. Experimentally, the tunable laser has high External-Cavity efficiency (22%) and high wavelength tuning accuracy (2 pm) throughout the 41.6 nm tuning range. Potential applications of the External-Cavity tunable laser include optical networks, optical sensing, and on-chip optoelectronic systems.
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Vibration measurement with a micromachined mirror in a very-short External Cavity laser
Sensors and Actuators A: Physical, 2004Co-Authors: Franck Chollet, Xuming Zhang, Ai Qun Liu, G. M. Hegde, Anand AsundiAbstract:We have fabricated, modeled and tested a displacement sensor based on an External Cavity laser with a micro-mirror integrated with a positioning actuator. We have developed an improved model for simulating the intensity change in the External Cavity laser when the feedback from the External mirror exceed 20% of the feedback from the laser facet. A special surface-micromachined mirror has been developed to obtain a very short External Cavity laser (≈ 10m) that allow removing all coupling optical elements in the External Cavity. During testing, we could verify the theoretical prediction and achieve a large relative feedback providing a strong intensity modulation. We observed a good angular tolerance suggesting a good manufacturability of the device. The tested device has a noise floor at 5 pm/√Hz above 500 Hz. This sensor could be used as a high sensitivity acceleration sensor.
John R. Andrews - One of the best experts on this subject based on the ideXlab platform.
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Electronically tunable single-mode External-Cavity diode laser.
Optics letters, 1991Co-Authors: John R. AndrewsAbstract:A six-stage birefringent filter placed in an External Cavity of an AlGaAs diode laser is used to scan the laser electronically over 10.3 nm, hopping single modes of the External Cavity. Continuous electronic tuning of the single mode over the free spectral range of the External Cavity, 182 MHz, is also demonstrated by using a variable-phase plate. All tuning mechanisms use nematic liquid-crystal electro-optic effects operating at
Evandro Conforti - One of the best experts on this subject based on the ideXlab platform.
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Asymmetric alignment-stabilized External-Cavity semiconductor laser.
Optics letters, 1992Co-Authors: Luiza M. R. Codá, J. P. Von Der Weid, Evandro ConfortiAbstract:We have demonstrated an alignment-stabilized asymmetric Cavity configuration for a grating-tuned External-Cavity semiconductor laser. The grating in the asymmetric Cavity has a 16-fold greater angular misalignment tolerance than in a conventional symmetric External-Cavity semiconductor laser. The tuning ranges are nearly the same for both cavities (approximately 30 nm).
Byungchil Kim - One of the best experts on this subject based on the ideXlab platform.
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Initial-state dependence of the route to chaos of an External-Cavity laser
Physical Review A, 2017Co-Authors: A. Locquet, Byungchil Kim, Daeyoung Choi, David S. CitrinAbstract:External-Cavity semiconductor lasers (ECLs), consisting of a laser diode in front of a mirror to reflect light back into the laser diode, are among the most important dynamical systems because of their ultrafast dynamics, their tunability, and the numerous existing applications. The dynamics of an ECL is greatly influenced by the existence and stability of numerous modes of the External Cavity. In such high-dimensional nonlinear systems, numerous attractors, located around various modes of the External Cavity, can coexist in phase space for a given set of parameters, a phenomenon called generalized multistability. In this work, we propose a procedure that allows one to select experimentally different modes of the External Cavity as different initial states. We use this procedure to reveal experimentally generalized multistability in an ECL through the demonstration that different routes to chaos exist in an ECL, depending on the initial state selected. In particular, we show that the famous quasiperiodic route to chaos is only observed for specific choices of initial conditions.
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Experimental route to chaos of an External-Cavity semiconductor laser
Physical Review A, 2015Co-Authors: Byungchil Kim, A. Locquet, Daeyoung Choi, D CitrinAbstract:We report experimental bifurcation diagrams of a semiconductor laser, biased well above threshold, subjected to External optical feedback. As feedback is increased, we see a quasiperiodic route to chaos interrupted by several windows of periodicity corresponding to limit cycles, differing in frequency by multiples of the External-Cavity free-spectral range that have developed around External-Cavity modes (ECMs) whose frequency is slightly larger than that of the solitary laser. Successive windows correspond to the transition between two limit cycles either on the same or neighboring ECMs. For larger feedback, the laser operates in a chaotic regime around numerous negatively shifted External-Cavity modes. These experimental observations detail the bifurcations leading to fully developed chaos in this system, and further provide detailed insight on the standard theoretical framework applied to these lasers.
A. Locquet - One of the best experts on this subject based on the ideXlab platform.
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Initial-state dependence of the route to chaos of an External-Cavity laser
Physical Review A, 2017Co-Authors: A. Locquet, Byungchil Kim, Daeyoung Choi, David S. CitrinAbstract:External-Cavity semiconductor lasers (ECLs), consisting of a laser diode in front of a mirror to reflect light back into the laser diode, are among the most important dynamical systems because of their ultrafast dynamics, their tunability, and the numerous existing applications. The dynamics of an ECL is greatly influenced by the existence and stability of numerous modes of the External Cavity. In such high-dimensional nonlinear systems, numerous attractors, located around various modes of the External Cavity, can coexist in phase space for a given set of parameters, a phenomenon called generalized multistability. In this work, we propose a procedure that allows one to select experimentally different modes of the External Cavity as different initial states. We use this procedure to reveal experimentally generalized multistability in an ECL through the demonstration that different routes to chaos exist in an ECL, depending on the initial state selected. In particular, we show that the famous quasiperiodic route to chaos is only observed for specific choices of initial conditions.
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Experimental route to chaos of an External-Cavity semiconductor laser
Physical Review A, 2015Co-Authors: Byungchil Kim, A. Locquet, Daeyoung Choi, D CitrinAbstract:We report experimental bifurcation diagrams of a semiconductor laser, biased well above threshold, subjected to External optical feedback. As feedback is increased, we see a quasiperiodic route to chaos interrupted by several windows of periodicity corresponding to limit cycles, differing in frequency by multiples of the External-Cavity free-spectral range that have developed around External-Cavity modes (ECMs) whose frequency is slightly larger than that of the solitary laser. Successive windows correspond to the transition between two limit cycles either on the same or neighboring ECMs. For larger feedback, the laser operates in a chaotic regime around numerous negatively shifted External-Cavity modes. These experimental observations detail the bifurcations leading to fully developed chaos in this system, and further provide detailed insight on the standard theoretical framework applied to these lasers.
