Demonstration of post-growth wavelength control of VCSELs using high-contrast gratings
Abstract
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 HCGVCSELs 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 HCGVCSELs 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- Other Electrical Engineering, Electronic Engineering, Information Engineering
- Semiconducting gallium
- VCSELs
- Optical interconnects
- Diffraction gratings
- High contrast grating
- Gallium arsenide
- CWDM
- Wavelength control
- Wavelength division multiplexing
- Sacrificial layer
- Threshold currents
- High-contrast gratings
- Optical waveguides
- High reflectivity
- Transceivers
- Electrically injected
- Surface emitting lasers