High reflectivity laser facets by deeply etched DBR buried with benzocyclobutene

Abstract

Lasers having a DBR facet on one side of the cavity were fabricated in a simple process using one step electron beam (EB) lithography and CH/sub 4//H/sub 2/-reactive ion etching (RIE). The DBR structure consists of deeply etched 3/spl lambda//4 wide grooves, which are buried with benzocyclobutene (BCB) polymer so as to reduce diffraction loss, spaced 3h/4 apart. The reflectivity of the DBR was estimated from the threshold current dependence on cavity length and an output power ratio from the front to the rear facets to be as high as 96% for 10 element DBR.