Monolithic integrated optoelectronic transmitter on GaAs with fully RIE GRINSCH laser diode

A fully functioning optoelectronic integrated circuit, a transmitter comprising an AlGaAs GRINSCH (graded-index separate confinement heterostructure) laser diode (LD), a back facet monitor diode, and a driving circuit made up of four MESFETs, has been successfully fabricated. The flexibility that can be attained with facets completely fabricated by reactive ion etching (RIE) is demonstrated on mutually perpendicular stripe lasers side-by-side on the same wafer. The circuits were made on semi-insulating GaAs wafers using two separate MBE (molecular-beam epitaxy) growth runs for the MESFETs and the laser diodes, respectively. More than 50% of the integrated circuits on the 3" wafer were fully functional, although some variation of the FET threshold voltage, transconductance, and the gain-guided LD threshold current was observed. Typical values were -1.5 V, 98 mS/mm, and 100 mA, respectively. Measured speeds of operation exceeded 1 Gb/s.<>