Several adaptive-optics techniques, based on the active modification of the optical properties of the laser cavity, were used to significantly reduce the time-to-full-brightness of solid-state lasers. Resonator re-configuration was achieved using a mechanical translation stage and both multi- and single-element deformable bimorph mirrors. Using these techniques the effects of thermally induced distortion in Nd:YLF and Nd:YAG lasers can be minimized and the warm-up time reduced by a factor of 3-6.

A controllable self-Raman laser using an adaptive optics (AO)-based control loop featuring an intracavity deformable mirror is reported. This method has the potential to alleviate thermal lensing within the Raman and laser gain media, and enable solid-state Raman lasers to reach new power levels. A proof-of-concept experiment using a Nd:YVO4 self-Raman laser and resulting in 18% enhancement of the first Stokes output power is reported. Moreover, wavelength selection between two Raman laser outputs (λ=1109 and 1176 nm) emanating from the 379 and 893 cm(-1) Raman shifts of YVO4, respectively, was achieved using this AO technique.

Imaging devices are very attractive as sensors in modern airborne platforms and there is a continuing trend toward widespread employment of imaging either alone or in combination with complementary technologies. In the civil domain, modern silicon CCD and CMOS image sensors are becoming extremely small, so that the package size of commercial miniature cameras is increasingly being dominated by the image forming optics, even if the latter is only a structure supporting a pinhole. Recently, there have been demonstrations of ultra-flat, extremely light weight sensors working in the visible region of the spectrum. Similar ideas for cameras developed to operate in the infra-red could help to drastically reduce the size, weight and cooling requirements of imaging, also offering substantial cost reductions. In addition, designs providing wide field-of-view can potentially eliminate the need for sightline steering hardware. This paper describes work on a biologically inspired imaging system offering a wide field of view, thanks to the use of a multi-aperture sensor based on micro-optics which can be used to observe simultaneously in different directions. Results from a near-infrared, narrowband demonstrator are reported.

We report on recent progress in the field of visible light communications including direct modulation of blue laser devices at data rates beyond 10 Gbit/s, and the transmission of 2.5 Gbit/s OOK data through water. We also discuss the advantages of operating with single mode laser devices and matched filtering at the receiver in the context of applications with significant solar background. The system performance for two types of directdetection receivers, a PIN detector and less conventional silicon Photomultiplier technology will be presented.

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