Using a Gaussian-to-flattop beam reshaper and a frequency-doubling crystal, we demonstrate highly efficient and spatially uniform pulse compression of 1mJ, ~100fs pulses from a regenerative Ti:sapphire amplifier. The technique has general applicability to all-bulk self-defocusing-type cascaded-quadratic compressors, providing a way to increase peak power and intensity for a wide range of amplified femtosecond pulsed lasers.

We demonstrate inhibition of the sidelobes of the axial point spread function in optical coherence tomography by shaping the power spectrum of the light source with a remaining power of 4.54 mW. A broadband amplified spontaneous emission source radiating at 1565 +/- 40 nm is employed in a free-space optical coherence tomography system. The axial point spread functions before and after optical spectral shaping are presented. Results show that spectral shaping of the source can inhibit sidelobes of the point spread function up to 12.9 dB, with an associated small increase of 2.2 dB in noise floor in the far field. The effect of spectral shaping on axial resolution is demonstrated according to three metrics. Image quality improvement is also illustrated with optical coherence tomography images of an onion before and after spectral shaping.

We report efficient, diode-pumped, self-frequency doubling (SFD) in the newly developed laser crystal Nd3+:YCa4O(BO3)3. More than 350 mW of fundamental output power at 1060 nm was achieved with a slope efficiency of 51%. With one watt of absorbed pump power, 62 mW of green cw laser emission at 530 nm was observed with proper phase matching. This initial performance, and the good optical properties of the crystalline host, are encouraging for the development of a high power diode-pumped SFD visible light laser source.

Spectral imaging involves capturing images at multiple wavelengths resulting in a data cube (x, y, λ) that allows materials to be identified by its spectral signature. While hyperspectral imagers can provide high spectral resolution, they also have major drawbacks such as cost, size, and the copious amounts of data in the image cube. Typically, the complete hyperspectral data cube provides little additional information compared to only 3-8 discrete (multiwavelength) imaging bands. We present two new approaches and related technologies where we are able to acquire spectral imaging data stacks quickly and cost-effectively. Our two spectral imaging systems represent different approaches integrated with standard CCD and CMOS imagers: sequential rotating filter wheels (RFWs) and lithographically patterned dichroic filter arrays (DFAs). The RFW approach offers the ability for rapid configuration of a spectral system, and a whole new level of self-contained image acquisition, processing and on-board display. The DFA approach offers the potential for ultra compact imagers with acquisition of images of multiple wavelengths simultaneously, while still allowing for processing and display steps to be built into the camera. Both approaches lend themselves production of multi-wavelength/spectral imaging systems with differing features and advantages.