No abstract

No abstract

We describe the preparation of InGaAsP/InP optical rib waveguides by maskless excimer laser projection etching. The process is based on the spontaneous chemical reaction of Cl2 etch gas with the InP surface at room temperature and subsequent laser-induced chloride evaporation. The spatial resolution is at least 1 μm. A typical etch rate is 0.45 nm/pulse or 540 nm/min at 20 Hz pulse repetition rate. Due to smooth surfaces, the optical attenuation of laser-etched waveguides is equivalent to that of conventionally etched guides. To demonstrate the utility of the process, we have also designed and successfully fabricated directional couplers from the same waveguide type according to the effective index method.