Long-wavelength InGaAsP/InP distributed feedback lasers incorporating gain-coupled mechanism

Author

Tsang, W.T. ; Choa, F.S. ; Wu, M.C. ; Chen, Y.K. ; Logan, R.A. ; Sergent, A.M. ; Burrus, C.A.

Author_Institution

AT&T Bell Labs., Murray Hill, NJ, USA

Volume

4

Issue

3

fYear

1992

fDate

3/1/1992 12:00:00 AM

Firstpage

212

Lastpage

215

Abstract

Successful operation of long-wavelength InGaAsP low-threshold-current gain-coupled DFB lasers was demonstrated by using an InGaAsP quaternary grating that absorbs the DFB (distributed feedback) emission. The amount of gain (loss)-coupling is controlled by the composition (bandgap) and thickness of the grating quaternary and the InP-spacer layer between the grating and the active layer. With optimally designed lasers, CW (continuous-wave) threshold currents were 10-15 mA (250- mu m cavity, as-cleaved), slope efficiency was approximately 0.4 mW/mA (both facets) and SMSR (side-mode suppression ratio) was as high as 52 dB. The laser operated in the same DFB mode with SMSR staying approximately 50 dB throughout the entire current range. At 100 degrees C, the CW threshold current stayed low, approximately 50 mA, and SMSR was approximately 40 dB. Results also indicate that the presence of gain-coupling removes the degeneracy in lasing wavelength.<>

Keywords

III-V semiconductors; diffraction gratings; distributed feedback lasers; gallium arsenide; gallium compounds; indium compounds; laser modes; semiconductor junction lasers; 10 to 15 mA; 100 degC; 50 mA; CW lasing; CW threshold current; DFB lasers; DFB mode; InGaAsP-InP; InP-spacer layer; active layer; as-cleaved; distributed feedback lasers; gain-coupled; gain-coupled mechanism; grating quaternary layer thickness; long-wavelength; low-threshold-current; quaternary grating; semiconductors; side-mode suppression ratio; slope efficiency; Distributed feedback devices; Gratings; Indium phosphide; Laser feedback; Laser modes; Laser theory; Performance gain; Phase modulation; Semiconductor lasers; Threshold current;

fLanguage

English

Journal_Title

Photonics Technology Letters, IEEE

Publisher

ieee

ISSN

1041-1135

Type

jour

DOI

10.1109/68.122369

Filename

122369