Photopumped green lasing on BeZnSeTe double heterostructures grown on InP substrates

Abstract

Double heterostructures ͑DHs͒ consisting of BeZnSeTe active and MgSe/BeZnTe superlattice cladding layers were fabricated on InP substrates by molecular beam epitaxy. By photoexciting the DHs, green lasing emissions at 548 nm were obtained at room temperature. The threshold excitation power density was 70 kW/ cm 2 , from which we estimated the threshold carrier density and threshold current density assuming a green laser diode ͑LD͒ with a BeZnSeTe active layer to be ͑1.4-4.6͒ ϫ 10 18 cm −3 and 0.22-0.73 kA/ cm 2 , respectively. The experiment proved the applicability of BeZnSeTe as an active layer of green LDs.

Measurements of the Weak UV Absorptions of Isoprene and Acetone at 261–275 nm Using Cavity Ringdown Spectroscopy for Evaluation of a Potential Portable Ringdown Breath Analyzer

“…In this particular experiment, the drop in the ringdown signal when the breath gas was injected inside the chamber was slightly larger than the drop in the ringdown signal when a 1.33 ppm acetone gas was measured. The acetone concentration in healthy human exhaled breath varies from 0.1-2.7 ppm [5,14,49,50], while isoprene has been reported to be in the range of few hundreds of ppb [14-18,43,50,51]; therefore, this result implies that there is a possibility of the contributions from other VOCs present in the exhaled breath. In general, most of the VOCs in breath gas are present in very low concentration as compared to acetone, isoprene, and CO 2 (CO 2 is about 5% in normal human breath gas).…”

Microchip laser converter based on InGaN laser diode and (Zn)CdSe quantum dot heterostructure

“…Blue, green, and red lasing at 497, 540, and 604 nm, respectively, was realized in ZnCdSe/ZnCdMgSe quantum well laser structures grown on InP substrate at optical pumping . Green‐to‐yellow photopumped laser emission from 538 to 570 nm was demonstrated in BeZnSeTe active layer heterostructures grown also on InP . The threshold excitation power density was approximately 30 kW cm −2 .…”

Investigation of p-side contact layers for II–VI compound semiconductor optical devices fabricated on InP substrates by MBE

“…II-VI compound semiconductors such as ZnCdSe, BeZnTe, and BeZnSeTe on InP substrates are very attractive for use in visible-toinfrared optical devices [1][2][3][4][5][6][7][8][9]. Using these materials, we are developing green and yellow laser diodes (LDs) and light-emitting diodes (LEDs) [3][4][5][6][7][8][9].…”

“…Using these materials, we are developing green and yellow laser diodes (LDs) and light-emitting diodes (LEDs) [3][4][5][6][7][8][9]. In the developments, lowering the contact resistance between (especially p-side) contact layers and electrodes is a crucial issue in obtaining high device performances.…”