Remote digital holography using a repeater laser for reference beam generation

Abstract

We propose a repeater laser (RL) method to generate a reference beam with low relative frequency instability and stable optical power for remote digital holography (DH), in which a measurement target is large scale such as the atmosphere or laid optical fibers. An RL, a laser phase-locked to a signal beam, plays the role of a repeater of the optical frequency, and a beam from it is used as a reference beam. As a proof of principle, we experimentally demonstrate wavefront measurements using a phase-only spatial light modulator as a measurement target with known phase distribution. Results show that the remote DH using the RL method achieves the same measurement accuracy as local DH.

Stable reference wave generation using a repeater laser for remote digital holography

“…We proposed a repeater laser (RL) method, 14) in which an another laser source, called an RL, 15) generates a wave phaselocked to an object wave as a reference wave. The phaselocking function requires a beat signal between a wave of the RL and a PWC in a split object wave to detect the phase and frequency difference between them.…”