Tunable distributed-feedback quantum-cascade lasers for gas sensing applications

被引：1

作者：

Gmachl, C ^{[1
]}

Capasso, F ^{[1
]}

Faist, J ^{[1
]}

Sivco, DL ^{[1
]}

Baillargeon, JN ^{[1
]}

Hutchinson, AL ^{[1
]}

Cho, AY ^{[1
]}

Namjou-Khaless, K ^{[1
]}

Cai, SM ^{[1
]}

Whittaker, EA ^{[1
]}

Kelly, JF ^{[1
]}

Sharpe, SW ^{[1
]}

Hartman, JS ^{[1
]}

机构：

[1] AT&T Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA

来源：

FABRICATION, TESTING, AND RELIABILITY OF SEMICONDUCTOR LASERS III | 1998年 / 3285卷

关键词：

D O I：

10.1117/12.307601

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

Continuously tunable single-mode emission of high performance quantum cascade (QC) lasers is achieved by application of the distributed feedback (DFB) principle. The devices are fabricated either as loss-coupled or index-coupled DFB lasers. Single-mode tuning ranges of approximate to 100 nm have been measured in both of the atmospheric windows at emission wavelengths around lambda approximate to 5 mu m and 8 mu m. Linear thermal tuning coefficients of 0.35 nm/K and 0.55 nm/K have been obtained above 200 K for lambda approximate to 5 mu m and 8 mu m, respectively. The side-mode suppression ratio is better than 30 dB. Pulsed single-mode operation has been achieved up to room temperature with peak power levels of 60 mW. The lasers also operated single-mode in continuous wave at temperatures above liquid Nitrogen temperature; a single-mode tuning range of 70 nm has been measured in the temperature range from 20 K to 120 K. The gas sensing capabilities of the QC-laser have also been demonstrated using both direct absorption and wavelength modulation techniques. A pulsed, room temperature, QC-DFB laser operating at lambda approximate to 7.8 mu m was used to detect N2O diluted in N-2. The detection limit was found to be approximate to 500 ppb-m. In addition, the high resolution capability of the QC-DFB lasers (at 77 K) has been demonstrated via continuous, rapid-scan, direct absorption measurement of the Doppler limited R(16.5) lambda doublet of NO at lambda approximate to 5.2 mu m.

引用

页码：144 / 153

页数：10