Ian R. Coddington

Coherent Measurements with Fiber-Laser Frequency Combs

The coherent and broad spectral output of fiber-laser frequency combs can be exploited for a variety of high-resolution measurements outside of conventional frequency metrology. We will discuss recent measurements in spectroscopy, ranging, and telecommunication components.

A portable dual frequency comb spectrometer for atmospheric applications

Dual frequency comb (DFC) spectroscopy is a new technique that combines broad spectral bandwidth, high spectral resolution, rapid data acquisition, and high sensitivity. In addition, unlike standard Fourier-transform spectroscopy, it has an almost ideal instrument lineshape function, does not require recalibration, and has no moving parts. These features make DFC spectroscopy well suited for accurate measurements of multiple species simultaneously. Because the frequency comb lasers can be well collimated, such a system can be used for long open-path measurements with path lengths ranging from hundreds of meters to several kilometers. This length scale bridges the gap between point measurements and satellite-based measurements and is ideal for providing information about local sources and quanitfying emissions.

Rapid, High Resolution Frequency Comb Measurements

Frequency combs serve as an extremely high accuracy reference across broad portions of the optical spectrum. Dual frequency combs harness this accuracy and allow for fast and highly flexible measurements of passive and active sources.

Low Noise Frequency Comb Based on an All-Fiber Polarization-Maintaining Figure-8 Laser

We present a frequency comb based on an all-fiber polarization-maintaining figure-8 laser. It is locked to an optical reference through an intracavity high-bandwidth electro-optical modulator and has a flat phase noise of -78 dBc/Hz.