Open AccessInvestigation of hybrid microlens integration with vertical-cavity surface-emitting lasers for free-space optical links
Author(s) -
Qi Fu,
Ngoi Kok Ann Bryan
Publication year - 2002
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.10.000413
Subject(s) - microlens , optics , materials science , vertical cavity surface emitting laser , collimated light , lens (geology) , laser , beam divergence , optoelectronics , numerical aperture , semiconductor laser theory , wavelength , laser beam quality , physics , laser beams
In a novel one-step process, a vertical-cavity surface-emitting laser (VCSEL, operation wavelength of 980 nm) is integrated with a hybrid microdiffractive lens by focused ion beam milling (FIBM) for use in freespace optical links. A hybrid microlens with a diameter of 100 m, numerical aperture of 0.56, and sag height of 4.196 m, combined with a diffractive lens with continuous relief and 6 annuli, was designed and fabricated in one step by FIBM on the back of a VCSEL with a GaAs substrate for beam collimation. A previous VCSEL integrated with a pure diffractive lens had a half-divergence angle of 0.6 degrees ; the half-divergence angle of the VCSEL with the hybrid microlens was improved to 0.3 degrees . Test results show that athermalization with respect to the variation in operating temperature can be realized with the hybrid microlens.