Quantum Device Laboratory (QDL) at OU is working on quantum engineered semiconductor structures in sub-nanometer scale for realizing functional devices and sub-systems with support from NSF, DoD, and DoE.
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Prof. Rui Q. Yang and PhD Student Yixuan Shen Present at CLEO 2024
Figure 1: Prof. Rui Q. Yang presenting his invited talk on mid-infrared interband cascade devices.
Figure 2: Yixuan Shen presenting his research on long-wavelength interband cascade lasers.
Charlotte, NC, May 2024 – Prof. Rui Q. Yang and PhD student Yixuan Shen recently attended the Conference on Lasers and Electro-Optics (CLEO) 2024, in Charlotte, North Carolina, USA.
Prof. Yang delivered an invited talk titled “Mid-infrared Interband Cascade Devices for Sensing Applications,” showcasing the latest advancements in mid-infrared interband cascade lasers, interband cascade infrared photodetector and their potential for various sensing applications (see Figure 1).
PhD student Yixuan Shen also made a contribution to the conference by presenting his research on “Long Wavelength Interband Cascade Lasers using Innovative Quantum Well Active Regions.” His presentation highlighted the use of innovative quantum well structures to achieve long-wavelength emission in interband cascade lasers (see Figure 2).
The CLEO conference is renowned for its comprehensive technical program that covers all aspects of laser science and photonics applications. The participation of Prof. Yang and Yixuan underscores our group’s mission to advancing the field of laser technology and fostering a collaborative research environment.
Recent publications
Continuous wave interband cascade lasers near 13 μm
Yixuan Shen, Rui Q. Yang, Samuel D. Hawkins, Aaron J. Muhowski
We report the demonstration of continuous-wave interband cascade lasers (ICLs) near 13 μm. The attained lasing wavelength of 13.2 μm at 92 K stands as the longest cw emission wavelength ever reported for III-V interband lasers. This achievement is attributed to the adoption of an innovative quantum well (QW) active region comprising strained InAs0.5P0.5 layers in contrast to the commonly used “W” QW active region, showing the potential of the modified QW active region with InAsP layers in improving device performance and extending wave- length coverage of ICLs.
Shot and Johnson noises in interband cascade infrared photodetectors
Rui Q. Yang, “Shot and Johnson noises in interband cascade infrared photodetectors”, Appl. Phys. Lett. 121, 51105 (2022)
Shot and Johnson noises are often incorrectly thought of as two independent noise sources. This incorrect picture has affected the evaluation of detectivities in interband cascade infrared photodetectors (ICIPs). In this work, a unified picture of shot and Johnson noises is developed for ICIPs based on a fundamental framework to understand the origin of Johnson noise and clarify the possible confusion between Johnson and shot noises. General, yet concise expressions are derived to evaluate the current noise power spectral density and detectivity for ICIPs even with complicated structures. Also, simple expressions for the signal current due to absorption of photons and the corresponding photon noise are derived, consistent with the previous results derived from alternative methods. Furthermore, a formula is derived to correctly evaluate the detectivity for conventional photodetectors under a reverse bias. The derived formulas with discussion are expected to improve the understanding of noises in ICIPs and other types of photodetectors and help us to appropriately evaluate their detectivities.
Continuous wave GaSb based ICL with hybrid cladding layers operated at RT and Above
Yixuan Shen ; Rui Q. Yang, Tetsuya D. Mishima ; Michael B. Santos ; Xiaojun Wang
We report the preliminary demonstration of continuous wave (cw) GaSb-based interband cascade lasers (ICLs) with hybrid cladding layers at high temperatures up to 80 °C near a wavelength of 3.72 μm. These ICLs have narrow-ridge widths of 7–11 μm with improved thermal dissipation compared to broad-area devices. They delivered a cw output power of more than 30 mW/facet at 20 °C and had a cw threshold current density of 270 A/cm2 with a voltage efficiency of 78% at 300 K. The obtained voltage efficiency of 78% is the highest ever reported among cw GaSb-based ICLs at room temperature, indicating an advantage of efficient carrier transport in the ICL with the hybrid cladding layers. The dependence of device performance on the narrow-ridge width and cavity length was investigated. The results suggested ways to further improve future devices.
High Performance Interband Cascade Lasers With Room Temperature Lasing Wavelengths Near 3.3 μm
Yixuan Shen ; Rui Q. Yang, Tetsuya D. Mishima ; Michael B. Santos ; Xiaojun Wang
We report significant advancements of interband cascade lasers (ICLs) with hybrid cladding layers. These 6-stage hybrid-cladding ICLs were able to lase in pulsed modes at temperatures up to 421 K, the highest ever reported among ICLs. The lasing wavelength was near 3.3 μ m at 300 K with a pulsed threshold current density of 114 A/cm2, the lowest for ICLs with similar wavelengths. Also, they achieved a high voltage efficiency of ~82% and a record-low threshold input power density of 312 W/cm2 at 300 K. Facet-uncoated narrow-ridge ICLs operated in continuous wave (CW) mode at temperatures up to 364 K (91°C), which is more than 20 K higher than the previous record for epi-up mounted ICLs. The obtained CW threshold current density of 205 A/cm2 at 300 K is similar to the previous record (~200 A/cm2 at 300 K) achieved by a superlattice-cladding 10-stage ICL with emission near the long-held optimal wavelength of ICLs at 3.6 μ m. Also, these ICLs at 300 K delivered CW output power of 25 mW/facet at 160 mA with substantially improved external quantum efficiency over previous ICLs at similar wavelengths.
