Excelitas

Photonic integrated circuits (PIC) have been used in Optical Coherence Interferometry (OCT) for main OCT interferometers and clock resonators but it is still a nascent field. Two of the most important metrics for such use are the scattering and dispersion. These can be measured using Optical Frequency Domain Reflectometry (OFDR) and Optical Frequency Domain Transmission (OFDT). We use a MEMS tunable VCSEL in the 1050 nm range to perform these measurements.

The continuous lasing process of a laser is sensitive to back reflected laser light, because it is disturbing the intrinsic stimulated emission process in the laser material. Faraday Isolators and Rotators are therefore commonly used to separate back reflected light from entering the laser cavity or the resonator. We present a new design of a Faraday Rotator for UV lasers with laser wavelengths of 343 and 355nm. This Faraday Rotator is suited for CW or pulsed UV lasers with typically averaged laser power up to few 10W range. In addition, we demonstrate the design option and feasibility of a 266nm Faraday Isolator.

A turnkey phase-sensitive swept-source OCT system requires stabilization of both the swept source and main signal interferometer. We have provided stable clocking and triggering of a 1050 nm swept MEMS VCSEL by mounting a solid clock etalon and volume Bragg grating optical trigger inside a temperature-stabilized butterfly package. A photonic integrated circuit (PIC) provides a phase-stable main interferometer near the sample. This system is only sensitive to the motion of sample, not to the fibers leading to and from the PIC.