This article describes recent research at the U.S. Naval Research Laboratory that focuses on the use of micro- and nanomachining techniques for photonic waveguide devices. By selectively etching a sacrificial layer that the waveguide core is supported by, in whole or in part, the waveguide obtains enhanced properties and functionality, such as mechanical flexibility, index contrast, birefringence, and evanescent field depth. We describe how these properties enable unique waveguide applications in areas such as cavity optomechanics, displacement sensing, electro-optics, and nonlinear optics.

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Selective implantation of silicon into GaAs is demonstrated as a simple method for modifying the response characteristics of low-doped planar GaAs photoconductors for optoelectronic circuits with varying requirements. Response times and sensitivities of the photoconductors were strongly dependent on the implantation dose and energy. Rise times and full width at half-maximum (FWHM) values of devices receiving low-dose implants were of the order of 40–150 ps. Rise times and FWHM values of devices which received higher dose implants were in the ranges 50–140 ps and 1–5 ns, respectively. The sensitivity of devices which received higher dose implants was about a factor of 100 (20 dB in optical power) greater than that of devices which received lower dose implants.

We report the incorporation of lactic acid etch mixtures in selective and nonselective etches suitable for InP-based III-V compound semiconductor heterostructure devices. Elimination and reduction of surface structures and controllable sidewall profiles are possible with solutions operating in the diffusion-limited, chemical activation-limited transition region.

Transient and total dose radiation effects were studied in InP JFETs under bias conditions. The transient responses in drain current, ID, and output power,