Top Grating, Surface-Emitting DFB Quantum Cascade Lasers in Continuous-Wave Operation

Author

Yinghui Liu ; Jinchuan Zhang ; Zhiwei Jia ; Danyang Yao ; Fengqi Liu ; Shenqiang Zhai ; Ning Zhuo ; Zhanguo Wang

Author_Institution

Key Lab. of Semicond. Mater. Sci., Inst. of Semicond., Beijing, China

Volume

27

Issue

17

fYear

2015

fDate

Sept.1, 1 2015

Firstpage

1829

Lastpage

1832

Abstract

We demonstrate room temperature, continuous-wave operation of top grating based surface-emitting distributed feedback quantum cascade lasers at λ ~ 4.8 μm. The second-order metal/semiconductor grating structure allows efficient surface emission for the transverse-magnetic-polarized light. The CW output power from the substrate facet reached 94 mW at 25 °C, with a low threshold current density of 1.21 kA/cm². Single-mode emission with a side-mode suppression ratio about 30 dB is continuously tunable by the heat sink temperature or injection current. A far-field radiation pattern with a small divergence angle of 0.58° × 16.2° is obtained. Our work may contribute to the fabrication approach for substrate-emitting distributed feedback lasers based on a very simple processing.

Keywords

current density; diffraction gratings; distributed feedback lasers; laser modes; laser tuning; light polarisation; quantum cascade lasers; surface emitting lasers; CW output power; divergence angle; far-field radiation pattern; heat sink temperature; injection current; power 94 mW; room temperature continuous-wave operation; second-order metal-semiconductor grating structure; side-mode suppression ratio; single-mode emission; substrate facet; temperature 25 degC; temperature 293 K to 298 K; threshold current density; top grating based surface-emitting distributed feedback quantum cascade lasers; top grating surface-emitting DFB quantum cascade lasers; transverse-magnetic-polarized light; Distributed feedback devices; Gratings; Optical surface waves; Quantum cascade lasers; Substrates; Surface emitting lasers; Surface waves; Semiconductor lasers; distribute feedback devices; distributed feedback devices; quantum cascade lasers;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/LPT.2015.2443780

Filename

7120912