A broadband, tunable, scanning IR-range etalon for FEL applications was designed, developed and tested. The design details and the results of the experimental tests are described and discussed. The design and mechanics of the etalon allowed to aligned the etalon mirrors with a precision not worse than λ/20, where λ = 0.63μ - the He-Ne laser wavelength, and during tuning and scanning, the mirrors remain parallel with the precision λ/20 ... λ/10, respectively. To minimize the resolvable bandwidth and improve the fringe contrast, the etalon may be used in a three-pass mode in which the light beam passes the etalon spacing three times by means of reflection from high precision corner reflectors.
展开▼
