| 摘要 |
A laser having an active region capable of lasings at different wavelengths includes an optical resonator cavity bounded at one end by one of several different wavelength-selective gratings. An adjustable mirror selects one of the wavelength-selective gratings by optically aligning the active region with the selected wavelength-selective grating. The position of the adjustable mirror is controlled by a combination of open loop-closed loop control. The open loop control includes a staircase generator, the closed loop control includes reference mirrors coacting with a feedback reflector in the back of the adjustable mirror for directing a control beam onto a position sensor. The length of the optical resonator cavity is dithered to retune the cavity for each wavelength selection. The beams produced at the various wavelengths are used, for example, to measure the optical energy content in a gas dynamic laser medium.
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