High-power VCSELs and arrays based on lithographic apertures with improved spectral and beam quality (Conference Presentation)

The growing demand for cost effective LIDAR sensors in automobile and military applications in LIDAR and free space optics could be met by compact and solid state, high power 2D VCSEL arrays. In this type of an array hundreds or more high power VCSELs can be monolithically integrated. This greatly reduces the cost over separately packaged lasers. In addition, beam quality and spectral quality make high power VCSELs important laser sources for free space data links. In this talk we introduce a different type of high power VCSEL that uses an oxide-free, lithographic aperture. The aperture enables a very low effective index change to help prevent trapping of internal modes that can occur with oxide VCSELs. The zero index aperture was designed to remove the internal ring modes that oxide VCSELs have, resulting in a lasing pattern with low optical loss. The novel zero index aperture is placed near the cavity spacer to improve its effect on confinement and electrical injection, and yet minimizing internal guiding of the optical mode. The VCSELs using the new aperture have been tested for their pulsed power, pulse response, device efficiency and beam quality. Dense arrays show high beam quality and record narrow spectral emission. Measured results of multi and single transverse mode VCSELs arrays with dense packing are also reported.