Astar’s Frequency Doubling Crystal
Crystal A solid with a structure that exhibits a basically symmetrical and geometrical arrangement. A crystal may already possess this structure, or it may acquire it through mechanical means. More than 50 chemical substances are important to the optical…
frequency doubling A nonlinear optical process in which the frequency of an optical beam is doubled coherently.
Frequency doubling is a frequently used technique for generating light with short wavelengths:
Green light with wavelength 532 nm can be generated by frequency-doubling the output of a neodymium- or ytterbium-based 1064-nm laser (→ green lasers). Green laser pointers are also usually based on this approach.
Many blue laser systems are based on a frequency-doubled laser in the 0.9-μm region (e.g. 914 nm from Nd:YVO4).
By further frequency doubling (or by sum frequency generation) still shorter wavelengths in the ultraviolet region (→ ultraviolet lasers) become accessible. The main challenges in this spectral region are the limited transparency range and (sometimes) limited durability of nonlinear crystal materials, and the strong chromatic dispersion (sometimes preventing phase matching or at least a large phase-matching bandwidth).
Frequency-doubled neodymium-based lasers can compete with large-sized argon ion lasers in terms of output power and beam quality, whereas having a far higher power efficiency and a longer lifetime.
For frequency doubling Crystal of ultrashort pulses, high single-pass conversion efficiencies are difficult to obtain at short wavelengths, because strong group velocity mismatch limits the interaction length, while optical damage limits the applicable optical intensities.
The phenomenon that an input wave in a nonlinear material can generate a wave with twice the optical frequency
Frequency doubling crystals: stock MgO:PPLN SHG crystals are available for a wide range of common pump laser wavelengths from 976 nm to 2100 nm.
MgO:LN (PPMgO:LN) crystals/modules are provided for frequency doubling/SHG application from 976 nm to 2300 nm.