A 5s-Time-Constant Temperature-Stable Integrator for a Tuneable PID Controller in LOC Applications

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Enabling Precision Astronomical Spectroscopy with Laser Frequency Combs

The laser spectroscopy enabled by optical frequency combs has been key to many developments in atomic and molecular physics and the advancement of related technologies such as atomic clocks and sensors. However, for several important spectroscopic scenarios, such as astronomy and remote sensing, phase-sensitive measurements against frequency combs are inaccessible as the light is broadband and thermal in origin. This work demonstrates how the precision and accuracy of optical frequency combs can be made to benefit spectroscopy in this regime. This thesis details the 30~GHz laser frequency comb designed and deployed for the Habitable Zone Planet Finder~(HPF) spectrograph. An achievement which overcame the challenges involved with high repetition rates, broad spectral bandwidths, and robust autonomous operation. Also included is an exploration of the theory and a presentation of related work associated with two of the most critical aspects of the astrocomb and of optical frequency combs in general: frequency stabilization and supercontinuum generation. A particular emphasis is given to the nonlinear optical theory necessary for numeric simulation of the second and third order nonlinear effects accessible in newly developed waveguide platforms. And in a different approach to the measurement of thermal light, frequency combs are brought to laser-based heterodyne radiometry for the purpose of near-infrared spectroscopy of the Sun. This simple and compact apparatus enables the prospect of high-resolution, quantum-limited spectroscopy of incoherent light wherever a comb can be generated