Abstract

There exists a great interest in an efficient source of mid-infrared (MIR) radiation between 3 μm and 10 μm and there are a number of nonlinear materials such as lithium niobate, GaSe, and others with large nonlinear coefficients in this range. Unfortunately, in all these materials the MIR experience strong absorption which severely limits the range where it can be generated efficiently.¹ For example, in lithium niobate, at 5.4 μm the absorption reaches 7 c m⁻¹² and the efficiency of frequency conversion is reduced by an order of magnitude.

© 1999 Optical Society of America