Author
M. Yi
Bio: M. Yi is an academic researcher. The author has contributed to research in topics: Semiconductor laser theory & Laser. The author has an hindex of 2, co-authored 3 publications receiving 53 citations.
Papers
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TL;DR: In this article, the phase locking characteristics of two coupled, ridge waveguide InP/InGaAsP diode lasers emitting at 1.2 μm were investigated experimentally by the observation of phase-locked modes (supermodes) in the near fields and distinct diffraction patterns in the far field.
Abstract: The phase‐locking characteristics of two coupled, ridge waveguide InP/InGaAsP diode lasers emitting at 1.2 μm were investigated experimentally. The phase locking of the lasers was verified by the observation of phase‐locked modes (supermodes) in the spectrally resolved near fields and distinct diffraction patterns in the far field. By independent control of the laser currents it was possible to vary continuously the mutual phase shift between the two phase‐locked lasers and thus steer the far‐field diffraction lobes. In addition, the separate current control could be utilized to obtain single longitudinal mode oscillation of the phase‐locked lasers. Variation in one of the laser currents resulted then in tuning of the wavelength of this single mode over a range of 90 A.
32 citations
TL;DR: In this article, the index-guided, buried-ridge InP/InGaAsP arrays are coupled via their evanescent optical fields, which makes it possible to avoid the occurrence of lower gain in the interchannel regions.
Abstract: Phase‐locked arrays of buried‐ridge InP/InGaAsP lasers, emitting at 1.3 μm, were grown by liquid phase epitaxy. The arrays consist of index‐guided, buried‐ridge lasers which are coupled via their evanescent optical fields. This index‐guided structure makes it possible to avoid the occurrence of lower gain in the interchannel regions. As a result, the buried‐ridge arrays oscillate mainly in the fundamental supermode, which yields single lobed, narrow far‐field patterns. Single lobed beams less than 4° in width were obtained from buried‐ridge InP/InGaAsP phased arrays up to more than twice the threshold current.
21 citations
TL;DR: In this article, a new type of buried heterostructure InGaAsP/InP lasers are described, which are grown by a single-step liquid phase epitaxy on Cd diffused mesa substrate.
Abstract: A new type of buried heterostructure InGaAsP/InP lasers grown by a single‐step liquid phase epitaxy on Cd diffused mesa substrate is described. These lasers exhibit excellent current and optical confinement. Threshold currents as low as 15 mA are achieved for a laser with a 2‐μm‐wide active region.
1 citations
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TL;DR: In this article, the parity-time symmetry breaking in an electrically injected, coherently coupled, vertical cavity surface emitting laser arrays was shown to be possible in terms of beam steering, mode evolution, and mode hopping as a consequence of the non-Hermiticity of the array analyzed by temporal coupled mode theory.
Abstract: We report parity-time (PT) symmetry breaking in electrically injected, coherently coupled, vertical cavity surface emitting laser arrays. We predict beam steering, mode evolution and mode hopping as a consequence of the non-Hermiticity of the array analyzed by temporal coupled mode theory with both asymmetric gain distribution and local frequency detuning. We present experimental confirmation of the predicted mode evolution, mode hopping and PT symmetry breaking with quantitative agreement with the theory.
80 citations
20 Mar 2017
TL;DR: In this paper, the parity-time symmetry breaking in an electrically injected, coherently coupled, vertical cavity surface emitting laser arrays was reported, with quantitative agreement with the temporal coupled-mode theory with both an asymmetric gain distribution and local frequency detuning.
Abstract: We report parity-time (PT) symmetry breaking in electrically injected, coherently coupled, vertical cavity surface emitting laser arrays. We predict beam steering, mode evolution, and mode hopping as consequences of the non-Hermiticity of the array, analyzed by the temporal coupled-mode theory with both an asymmetric gain distribution and local frequency detuning. We present experimental confirmations of the predicted mode evolution, mode hopping, and PT symmetry breaking with quantitative agreement with the theory.
77 citations
TL;DR: In this article, the authors review the current state of phase-locked array design with emphasis on the means for achieving fundamental mode operation, and the potential of various array structures to operate in a single, diffraction limited output beam is evaluated.
Abstract: Semiconductor diode lasers can be combined into monolithic phase-locked arrays that operate to continuous-wave (CW) powers in excess of 1 W and exhibit well-defined output beams to hundreds of mW. Applications of arrays include high-speed optical recording, high-speed printing, free-space communications, and efficient pumping of solid-state lasers. The authors review the current state of phase-locked array design with emphasis on the means for achieving fundamental mode operation. Models for understanding and predicting the behavior of phase-locked arrays are discussed, and the potential of various array structures to operate in a single, diffraction-limited output beam is evaluated.
57 citations
TL;DR: In this article, the authors demonstrate highly controllable steering of a coherent laser beam produced by a 2 2 array of emitters by electronically addressing the array elements independently, resulting in the angular deflection of the central peak of the in-phase array supermode.
Abstract: Photonic crystal vertical-cavity surface-emitting laser arrays can be designed to lase only in the in-phase array supermode. By electronically addressing the array elements independently, the relative phases between the emission from each element can be altered. The shift in relative phase results in the angular deflection of the central peak of the in-phase array supermode. We demonstrate highly controllable steering of a coherent laser beam produced by a 2 2 array of emitters.
55 citations
TL;DR: In this paper, the lateral-mode behavior of a semiconductor-laser array is analyzed after including the effect of injected charge carriers on the active-layer dielectric constant, and the resulting mode profile incorporates the effects of gain guiding, carrier-induced index antiguiding, and built-in index guiding.
Abstract: The lateral‐mode behavior of a semiconductor‐laser array is analyzed after including the effect of injected charge carriers on the active‐layer dielectric constant. The wave equation is solved self‐consistently and the lowest‐threshold lateral supermode is obtained by treating the whole array as one unit. The resulting mode profile incorporates the effects of gain guiding, carrier‐induced index antiguiding, and built‐in index guiding. The analysis is therefore applicable to gain‐guided as well as index‐guided arrays; near‐ and farfields for both kinds of arrays are obtained and compared to those obtained without gain‐loss considerations using the plane‐wave diffraction theory or the coupled‐mode theory. For gain‐guided arrays, carrier‐induced antiguiding plays an important role and leads to a transition from twin‐lobe to three‐lobe farfields for closely spaced, narrow array elements. For weakly index‐guided arrays the in‐phase or out‐of‐phase coupling between neighboring elements can occur depending on whether the gain is laterally homogeneous or not. The calculated results are in qualitative agreement with the reported experimental observations. The present analysis is useful to understand the role of various guiding mechanisms as well as to provide guidelines for the device optimization.
51 citations