We report a multi-wavelength passive filter working in the 1.3 μm range, fabricated by a post-growth technique based on the combined lateral-vertical steam oxidation of AlGaAs layers within a microcavity. Wafers are photolithographically patterned and etched through the top to create mesa structures which are oxidized from both edges, and control of resonant wavelength is achieved through mesa width, thickness and compositional control of intracavity layers to be oxidized, and oxidation conditions. Microreflectivity measurements of the processed devices show that in this wavelength range it is possible using this approach to control the resonant wavelength over a range of about 52 nm.
- wavelength tuning
- optical microcavity