Multiple-Wavelength Vertical-Cavity Surface-Emitting Lasers by Grading a Spacer Layer for Short-Reach Wavelength Division Multiplexing Applications

Abstract

We propose and demonstrate a simple and unique method to fabricate the multiple-wavelength vertical-cavity surface-emitting lasers (VCSELs) emitting at 980 nm by grading only the first low-index spacer layer of SiO2/Ta2O5 dielectric mirror. A multi step exposure to UV lithography followed by selective wet chemical etching has been applied to create spacer layer gradients. We have successfully realized equally spaced four-channel VCSELs with wavelength span exceeding 30.0 nm by grading a 230.0 nm spacer layer and achieved single mode lasing with a side mode suppression ratio in excess of 30.0 dB.

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

“…However, these techniques are not suitable for small-footprint dense VCSEL arrays with arbitrary layout. Various techniques for post-growth intra-cavity phase tuning have also been investigated, including lateral-vertical oxidation [10] and deposition or thinning of an intra-cavity phase tuning layer prior to the deposition of a dielectric top DBR [11,12]. Another possibility is to replace the top DBR with a #247486 subwavelength high-contrast grating (HCG) and make use of the dependence of the HCG reflection phase on the grating parameters.…”

High-Power Bottom-Emitting Vertical-Cavity Surface-Emitting Lasers under Continuous-Wave, Quasi-Continuous-Wave, and Pulsed Operation

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] A continuous-wave (CW) room-temperature output power of 1.95 W with 500 m aperture size was reported, 14) and a record output power of 3 W with an aperture size of 350 m was achieved in Princeton Optronics. 15) In order to further increase the output power, 2D arrays were fabricated.…”

“…V ertical-cavity surface-emitting lasers (VCSELs) are becoming strong competitors to conventional edgeemitting lasers due to their advantages such as low threshold current, circular light-output mode, high packaging density for two-dimensional (2D) arrays, and single longitudinal mode emission. [1][2][3][4][5][6][7][8][9][10][11][12][13] A continuous-wave (CW) room-temperature output power of 1.95 W with 500 m aperture size was reported, 14) and a record output power of 3 W with an aperture size of 350 m was achieved in Princeton Optronics. 15) In order to further increase the output power, 2D arrays were fabricated.…”