Toshikazu Onishi

Continuous Wave Operation of GaN Vertical Cavity Surface Emitting Lasers at Room Temperature

We report on continuous wave lasing characteristics of GaN vertical cavity surface emitting lasers (VCSELs). The VCSEL operates at room temperature under current injection by using highly reflective distributed Bragg reflectors (DBRs) made up of transparent <formula formulatype=inline><tex Notation=TeX>

Enhanced responsivity in a novel AlGaN / GaN plasmon-resonant terahertz detector using gate-dipole antenna with parasitic elements

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High power terahertz emission from a single gate AlGaN/GaN field effect transistor with periodic Ohmic contacts for plasmon coupling

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High-speed 850 nm AlGaAs/GaAs vertical cavity surface emitting laser with low parasitic capacitance fabricated using BCB planarization technique

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Polarization Control of Vertical-Cavity Surface-Emitting Lasers by Utilizing Surface Plasmon Resonance

</tex></formula> film stacks. Together with high reflectivity and the wide stop band of the DBR, the long cavity of 6 <formula formulatype=inline><tex Notation=TeX>

Polarization Control of VCSEL Array by Metal Nanoholes at Rectangular Lattice Utilizing Surface Plasmon Resonance

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Monolithically integrated 780-nm-band high-power and 650-nm-band laser diodes with real refractive index guided self-aligned structure

</tex></formula> allows multimode lasing oscillation with narrow mode spacing of 2.9 nm. In addition, a short cavity structure of 2 <formula formulatype=inline> <tex Notation=TeX>

Temperature-stable operating current of surface plasmon VCSELs with metal nanohole arrays

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Low threshold current 850nm surface plasmon VCSEL with sub-micron metal hole arrays

</tex></formula> is fabricated and shows quasi-single mode operation. The spacing of the lasing modes shows a clear dependence of the actual cavity lengths with fairly good agreement to theory taking account of the refractive index dispersion.

Semiconductor laser device and method for fabricating the same

Plasmon-resonant terahertz (THz) detection using heterojunction field effect transistors (HFETs) is a promising method to enable compact and efficient THz detectors which can be applied to real-time imaging systems or THz spectroscopic analysis [1–2]. So far, the plasmon-resonant detectors which receive sub-THz and THz radiation at a gate bonding-wire or an external antenna have been reported [3–5]. However, the signal transmission from the antenna to the FET causes large propagation loss which degrades the sensitivity. In this paper, we present a novel AlGaN / GaN heterojunction FET which can detect THz radiation directly at a gate electrode with high responsivity.