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Analog, non-mechanical beam-steerer with 80 degree field of regard

2008; SPIE; Volume: 6971; Linguagem: Inglês

10.1117/12.783766

1996-756X

Scott Davis, George Farca, Scott D. Rommel, Alan Martin, Michael H. Anderson,

Fern and Epiphyte Biology

We are presenting a novel electro-optic architecture for non-mechanical laser beam steering with a demonstrated 80 degrees of steering in a chip-scale package. To our knowledge this is the largest angular coverage ever achieved by non-mechanical means. Even higher angular deflections are possible with our architecture both in the plane of the waveguide and out of the waveguide plane. In the present paper we describe the steering in the plane of the waveguide leaving the out-of-plane scanning mechanism to be detailed in a subsequent publication. In order to realize this performance we exploit an entirely new electro-optic architecture. Specifically, we utilize liquid crystals (LCs), which have the largest known electro-optic response, as an active cladding layer in an LC-waveguide geometry. This architecture exploits the benefits of liquid crystals (large tunable index), while circumventing historic LC limitations. LC-waveguides provide unprecedented macroscopic (>1 mm) electro-optic phase delays. When combined with patterned electrodes, this provides a truly analog, "Snell's-law-type" beam-steerer. With only two control electrodes we have realized an 80 degree field of view for 1550 nm light. Furthermore, the waveguide geometry keeps the light from ever coming into contact with an ITO electrode, thereby permitting high optical power transmission. Finally, the beamsteering devices have sub-millisecond response times.