Interferometric displacement sensors require light sources with applicable properties, yet compact and cost effective to deploy over multiple individual sensor units instead of using large-cost laboratory laser sources. Could we use small-package Vertical Cavity Surface Emitting Lasers (VCSELs) [1, 2] or laser diodes for displacement sensor light sources?

This/these short-term Physics project/projects looks to experimentally investigate whether commercial VCSELs or laser diodes can have:

1. A coherence length of ~ 20cm - tested via a table-top Michelson interferometer
2. Good Gaussian beam output shape - tested via interrogation with a table-top optical cavity
3. Laser frequency stability/noise - tested via beatnote/phasemeter measurement

[1] B. Johnson et al., "Tunable 1060nm VCSEL co-packaged with pump and SOA for OCT and LiDAR," Proc. SPIE 10867 (2019), doi: 10.1117/12.2510395

[2] C. Burgner et al, "Reliable widely tunable electrically pumped 1050nm MEMS-VCSELs with amplifier in single butterfly co-package," Proc. SPIE 11228 (2020), doi: 10.1117/12.2549050

Completion of the second year Physics Lab program would be very useful, but not essential.