Abstract

Free electron lasers display special promise as very widely tunable coherent sources in the middle and far infrared.^1,2 The free electron laser is of special interest at longer wavelengths because the accelerator and electron beam requirements are greatly relaxed compared to FEI. s in the visible and ultraviolet, potential tuning ranges of 5 to 1 or larger appear feasible^2,3 and the availability of other laser or nonlinear optical sources with competitive tunability and wavelength coverage in this region appears limited.

© 1991 Optical Society of America