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- Kini Manjeshwar, Sushanth, 1990, et al.
(författare)
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Integrated microcavity optomechanics with a suspended photonic crystal mirror above a distributed Bragg reflector
- 2023
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Ingår i: Optics Express. - 1094-4087 .- 1094-4087. ; 31:19, s. 30212-30226
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Tidskriftsartikel (refereegranskat)abstract
- Increasing the interaction between light and mechanical resonators is an ongoing endeavor in the field of cavity optomechanics. Optical microcavities allow for boosting the interaction strength through their strong spatial confinement of the optical field. In this work, we follow this approach by realizing a sub-wavelength-long, free-space optomechanical microcavity on-chip fabricated from an (Al,Ga)As heterostructure. A suspended GaAs photonic crystal mirror is acting as a highly reflective mechanical resonator, which together with a distributed Bragg (DBR) reflector forms an optomechanical microcavity. We demonstrate precise control over the microcavity resonance by change of the photonic crystal parameters. We find that the microcavity mode can strongly couple to the transmissive modes of the DBR. The interplay between the microcavity mode and a guided resonance of the photonic crystal modifies the cavity response and results in a stronger dynamical backaction on the mechanical resonator compared to conventional optomechanical dynamics.
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| 2. |
- Shi, Zhangyong, et al.
(författare)
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Photoluminescence mapping of mid-wave infrared InAs/GaSb type II superlattice: Influence of materials and processes on spatial uniformity
- 2023
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Ingår i: Journal of Alloys and Compounds. - : Elsevier BV. - 0925-8388. ; 947
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Tidskriftsartikel (refereegranskat)abstract
- The imaging performance of infrared focal plane array (FPA) is limited by the non-uniformity of the in-plane response of InAs/GaSb type II superlattices (T2SL) consisting of a few hundred or more thin layers. Fundamentally, the non-uniformity results from the materials’ property variation and process fluctuations over an area of a square centimeter. Thus, the influence of materials and processes on the uniformity of internal response is necessary to accurately detect and evaluate to improve the imaging performance of an FPA detector. In this work, spatially resolved photoluminescence (PL) was implemented to detect the microscale mesa pixels, and the effects of materials and processes on spatial uniformity were studied for the first time. Modulated PL-mapping technology based on step-scan Fourier transform infrared spectrometry was used to extract parameters from each test spectrum, such as PL peak energy, linewidth, and integral intensity, which were then analyzed by 2D spatial mapping. Results showed that the variation of T2SL material properties accounted for 29% of the non-uniformity, and the remaining 71% resulted from the process fluctuation. In particular, the etching process had a great influence on the uniformity. The non-uniformity of the integral intensity of the sample after etching increased by 2.44 times compared with that before etching. Thereafter, a layer of SiO2 film was deposited to passivate the surface. The results showed that the non-uniformity returned to the level before etching, which directly proves that the passivation process can improve the response uniformity of the infrared FPA detector.
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