Controlling the Spatial Coherence of Lasers for Imaging and Sensing
Technical Report,15 Sep 2016,14 Sep 2019
Yale University New Haven United States
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The goals of this project were to build on our earlier work demonstrating an on-chip semiconductor laser source which generated emission with low spatial coherence, providing a uniquely efficient illumination source for speckle-free imaging and other optical tasks. In our first successful design, the laser was based on a D-cavity shape with chaotic ray dynamics, which enhanced the number of lasing modes. Low spatial coherence was achieved, however the D Laser did not provide a directional output beam, making it an inefficient source. In the current project we proposed to design new laser cavities with low spatial coherence and directional emission, and to also demonstrate the ability to tune in situ the number of lasing modes and hence the degree of spatial coherence of the output. Tunable coherence is important for achieving optimal illumination for applications such as holography. We continued to study chaotic cavity lasers but in the past year also proposed a new onchip cavity design with stable axial lasing modes promoting directional emission, and performed ab initio simulations to find the geometry cavity stability parameter that maximized the number of lasing modes.
- Optical Detection and Detectors
- Lasers and Masers