Dual Wavelength Wave Plates

Specifications:

Material: Quartz Crystal
Diameter Tolerance: +0.0/-0.15mm
Parallelism: < 1 arc second
Surface Quality: 20-10 scratch and digs
AR Coating: Dual wavelength AR coating on both sides
Part Number: WPD

Dual wavelength wave plates are widely used on Third Harmonic Generation systems (THG). When you need a NLO crystal for type II Second Harmonic Generation system (SHG) (o+e—e), and a NLO crystal for type II THG (o+e—e), the output polarization from the SHG can not be used for the THG. Dual wavelength wave plates work like polarizing rotators, they can rotate the polarization of one beam and keep another beam’s polarization constant. Also the dual wavelength wave plate can be applied to the following systems:

1. Type II SHG + Type II THG
2. Type II SHG + Type I THG
3. Type I SHG + Type I THG

For example, if we use KTP as the SHG type II and LBO as the THG type II, the polarization of the output beam from the KTP is not optimized for the THG type II. However, when we use a dual wavelength wave plate (as seen in the drawing), it can change the 532nm beam to a special angle polarization but the 1064nm beam will remain constant.