Relayed-loop optical scan amplification

Abstract

Many modern sensing, processing, and fabrication technologies depend upon the sequential scanning of laser light. Due to inertial, thermal, and electrical limitations, the speed of a typical laser deflector is inversely related to its optical invariant and therefore the number of resolvable spots it can address. Passive optical systems have been developed that can effectively double the optical invariant and maximum throughput of a single deflector. We present a method for increasing the effective optical invariant beyond 2$\times$ by repeated relaying of the deflected beam onto the deflector in an optical loop created within a cavity. We use this Relayed-Loop Optically Amplified Deflection (ReLOAD) approach to accomplish 8$\times$ amplification of electro-optical (EO) deflection, a deflection technology with unparalleled speed, but limited optical invariant. Using ReLOAD, we demonstrate 10 kHz frame rate imaging, 1 MHz line scan rate, and $\mu$s step times across an addressable space well beyond the capabilities of typical electro-optical deflectors.