title: Two-dimensional integration of a vertical-cavity surface-emitting laser and photodetectors for position sensing.
abstract: Noncontact long-range position sensing is desirable for a number of applications. We have designed and fabricated a monolithically integrated vertical-cavity surface-emitting laser (VCSEL) and p-type/intrinsic/n-type (PIN) photodetectors for optical position sensing. Calculations using the reflection from a periodic metallic corrugation as a position gauge indicate resolution in the submicron regime. High device uniformity is obtained using novel fabrication techniques. We observe a threshold current of 0.52 mA for the VCSELs and a detector responsivity of 0.38 A/W at 840 nm. The optical cross talk between VCSELs and detectors is also quantified.
authors.affiliation: Micro and Nanotechnology Laboratory, Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, 208 North Wright Street, Urbana, Illinois 61801, USA. giannopo@uiuc.edu
authors.forename: Antonios V
authors.initials: AV
authors.lastname: Giannopoulos
authors.forename: Ansas M
authors.initials: AM
authors.lastname: Kasten
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Long
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.forename: Kent D
authors.initials: KD
authors.lastname: Choquette