Publications
Fluidic microoptics with adjustable focusing and beam steering for single cell optogenetics
Summary
Summary
Electrically controlled micron-scale liquid lenses have been designed, fabricated and demonstrated, that provide both adjustable focusing and beam steering, with the goal of applying them to optogenetic in vivo mapping of brain activity with single cell resolution. The liquid lens is formed by the interface between two immiscible liquids which...
Spatially-resolved individual particle spectroscopy using photothermal modulation of Mie scattering
Summary
Summary
We report a photothermal modulation of Mie scattering (PMMS) method that enables concurrent spatial and spectral discrimination of individual micron-sized particles. This approach provides a direct measurement of the "fingerprint" infrared absorption spectrum with the spatial resolution of visible light. Trace quantities (tens of picograms) of material were deposited onto...
High efficiency coherent beam combining of semiconductor optical amplifiers
Summary
Summary
We demonstrate 40 W coherently combined output power in a single diffraction-limited beam from a one-dimensional 47-element array of angled-facet slab-coupled optical waveguide amplifiers at 1064 nm. The output from each emitter was collimated and overlapped onto a diffractive optical element combiner using a common transform lens. Phase locking was...
Diffractive beam combining of a 2.5-kW fiber laser array
Summary
Summary
Five 500-W fiber amplifiers were coherently combined with 79% efficiency using a diffractive optical element (DOE) combiner, generating a single beam whose M^2 = 1.1 beam quality exceeded that of the inputs.
Coherent combining of a 4 kW, eight-element fiber amplifier array
Summary
Summary
Commercial 0:5kW Yb-doped fiber amplifiers have been characterized and found to be suitable for coherent beam combining. Eight such fiber amplifiers have been coherently combined in a tiled-aperture configuration with 78% combining efficiency and total output power of 4kW. The power-in-the-bucket vertical beam quality of the combined output is 1.25...