Publications by authors named "Chengao Yang"

Antimonide laser diodes, with their high performance above room temperature, exhibit significant potential for widespread applications in the mid-infrared spectral region. However, the laser's performance significantly degrades as the emission wavelength increases, primarily due to severe quantum-well hole leakage and significant non-radiative recombination. In this paper, we put up an active region with a high valence band offset and excellent crystalline quality with high luminescence to improve the laser's performance.

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A bias-selectable near-infrared (NIR) and extended short wavelength infrared (eSWIR) dual-band bandgap engineered GaAsSb/AlGaAsSb/T2SL (InGa As/GaAsSb) infrared photodetector, vertically stacked in a monolithic grown on InP substrate, is demonstrated. GaAsSb NIR sub-detector and T2SL eSWIR sub-detector are operated under small forward and reverse bias, respectively. The GaAsSb sub-detector functions within the NIR spectrum, with a 100% cutoff wavelength of 1.

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Achieving high operating temperature (HOT) plays a crucial role in miniaturizing type-II superlattice (T2SL) mid-wavelength infrared (MWIR) focal plane arrays (FPAs). However, their full potential has yet to be realized due to a lack of complete understanding of their operation from the perspective of detection principles. Here, by investigating the photon transmission path and optoelectronic performance of the simulated devices, a detailed noise equivalent temperature difference (NETD) model of the T2SL MWIR FPAs was established.

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Thanks to high performance above room temperature, antimonide laser diodes have shown great potential for broad application in the mid-infrared spectral region. However, the laser`s performance noticeably deteriorates due to the reduction of carrier confinement with increased emission wavelength. In this paper, a novel active region with higher carrier confinements both of electron and hole, by the usage of an indirect bandgap material of AlGaAsSb as the quantum barrier, was put up to address the poor carrier confinement of GaSb-based type-I multi-quantum-well (MQW) diode lasers emission wavelength above 2.

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In this paper, we put up a robust design of a stable single-mode-operated GaSb-based laser diode emitting around 1950nm. This novel design structure with socketed ridge-waveguide enables a simple fabrication and batch production of mid-infrared laser diodes on account of the mere usage of standard photolithography. By introducing micron-level index perturbations distributed along the ridge waveguide, the threshold gains of different FP modes are modulated.

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GaSb-based single-transverse-mode narrow ridge waveguide (RW) lasers with high power and simultaneous good beam quality have broad application prospects in the mid-infrared wavelength region. Yet its design and formation have not been investigated systematically, while the beam characteristics that affect their suitability for specific applications remain rarely analyzed and optimized. The present work addresses these issues by theoretically establishing a waveguide parameter domain that generalizes the overall possible combinations of ridge widths and etch depths that support single-transverse-mode operation for GaSb-based RW lasers.

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In this article, we present a tunable GaSb-based blazed grating external cavity laser (BG-ECL) with high spectral purity and high output power single-mode operation around 1940nm. The drastic increase in spectral selectivity and optical power results from the employment of a single-transverse-mode operating narrow ridge waveguide laser diode with an optimized AR coating on the front facet. The stable fundamental spatial mode output beam from the laser diode enables efficient collimation and high coupling efficiency with the blazed grating, leading to stronger wavelength-selective feedback.

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