Fiber coupled acousto-optic modulators for near UV and blue wavelength applications

Abstract

We present results from the development of a fiber-coupled Acousto-Optic modulator (Fiber-Q®) operating at near-UV and blue wavelengths. A conventional TeO2 based Bragg diffraction design is introduced for short wavelengths optical input. Pure silica core single mode fibers (both Polarisation Maintaining (PM) and non-PM) are used as coupling fibers for their transmission at these wavelengths, and to avoid the possibility of photo darkening. The end of the fibers are fused with silica end-caps, lowering the power density on their fiber-air interfaces to achieve a higher power handling. The Fiber-Q® can be optimized for multiple wavelengths (including 397nm or 422nm) and can accept power levels of up to 100mW. A hermetically sealed package is selected to provide a clean in-package environment thus protecting the optics from damage caused by external contamination. In this presentation we report details of the design, and test results of a fiber-coupled Acousto-Optic modulator that demonstrates the performance required for use in ion-trap quantum information processing applications.