Demonstration of post-growth wavelength control of VCSELs using high-contrast gratings

Haglund, E. ; Gustavsson, J.S. ; Bengtsson, J. ; Haglund, A. ; Larsson, A. ; Fattal, D. ; Sorin, W. ; Tan, M.

HP Development Company

关键词: High Contrast Grating;    VCSELs;    CWDM;    Optical interconnects;   

RP-ID  :  HPL-2015-70

学科分类：计算机科学（综合）

美国|英语

来源: HP Labs

【 摘 要 】

We demonstrate post-growth wavelength setting of vertical-cavity surface-emitting lasers (VCSELs) using high-contrast gratings (HCGs). By fabricating HCGs with different duty-cycle and period, the HCG reflection phase can be varied, in effect giving different optical cavity lengths for HCG-VCSELs with different grating parameters. This enables fabrication of monolithic multi-wavelength HCG-VCSEL arrays for wavelength-division multiplexing (WDM). The GaAs HCG is suspended in air by selective removal of an InGaP sacrificial layer. Electrically injected 980-nm HCG- VCSELs with sub-mA threshold currents indicate high reflectivity from the GaAs HCGs. Lasing over a wavelength span of 15 nm was achieved, enabling a 4- channel WDM array with 5 nm channel spacing. Device design, fabrication and experimental proof-of-concept are presented.