| 摘要 |
<p>An optical beam steering device (10) incorporates a laser (12), three Brillouin shifters (22 to 26, 44 to 48, 54 to 58), a four wave mixing cell (40) and a low power beam steering device (62). The first shifter (22 to 26) and the mixing cell (40) contain TiCl 4, and the other shifters (44 to 48, 54 to 58) contain 20 % CCl4/80 % CS2. The first and third shifters (22 to 26, 54 to 58) frequency downshift the laser beam (16) by δξA and δξB respectively. Light (16') from the first shifter (22 to 26) is amplified and provides a first pump beam input to the mixing cell (40). It then passes to the second shifter (44 to 48), for frequency downshifting by δξB and returns as a second cell pump beam (16''). Light (18') from the third shifter (54 to 58) passes via the low power beam steering device (62) to the cell (40) as a weak input signal beam (18''). The cell (40) responds to the pump beams (16', 16'') and signal beam (18'') by generating a high power beam (68) which is a phase conjugate of the signal beam (18'') and retraces part of its steered path.</p> |
