The MZI-001 is a fiber pigtailed compact Mach-Zehnder interferometer, based on freespace optics, for detecting changes in optical frequency. The device comes with two fast photodetectors for the balanced detection of the two complementary outputs of the interferometer. The free spectral range or zero-cross spacing of the device is accurately defined to within 4%, a clear advantage over the all-fiber approach. In addition, the zero-cross spacing can be selected from 5 GHz to as high as 50 GHz when ordering, making it flexible for system integration. Finally, the MZI-001's free-space optical design eliminates the polarization sensitivity commonly associated with all-fiber interferometers. The MZI-001 is ideal for applications in wavelength-swept light sources for determining their instantaneous frequencies, in OCT systems as a frequency clock for system triggering, in fiber sensors for detecting sensing signal spectral drift, and in coherent communication systems for detecting frequency drifts of the lasers.
