Waveplate
Dual Wavelength Waveplates
Dual wavelength waveplates are THG-PR polarization rotators and used to manage the polarizations of laser beams to obtain maximum conversion efficiency of third harmonic generations (THG), i.e., 1064 nm + 532 nm > 355 nm.
Generally, type I frequency-doubler (oo-> e) + type II frequency-tripler ( oe-> e) will be the best design for THG which needs no polarization rotator. However, when a type II KTP crystal is used as frequency-doubler and type II LBO as frequency-tripler (see the Figure), the laser polarizations coming out from KTP are not optimized for THG. How to change it into its optimum? CASIX THG-PR polarization rotator can do it!
Common 1/2 wave
phase retardation plate could only rotate the polarization of
532 nm to a specific angle. However, the linear polarization
of 1064 nm will be distorted to be elliptical. The THG-PR rotator
is specially designed to maintain the linear polarization of
1064 nm (l plate) and change simultaneously 532 nm (l/2 plate)
to the angle you need. The THG-PR can be applied to:
1. Type II (SHG) + Type II (THG)
2. Type I (SHG) + Type I (THG)
3. Type II (SHG) + Type I (THG)
Specifications:
Material: Crystal Quartz
Dimension Tolerance: +0.0, -0.2
mm
Wavefront Distortion: <l/8
@ 633 nm
Retardation Tolerance: <l/300
Parallelism: <3 arc second
Surface
Quality: 20/10 scratch and dig
Dual Wavelength AR Coating:
R<0.2% at fundamental wavelength & R<0.5% at SHG wavelength
| Aperature f (mm) | 10.0 | 12.7 | 15.0 | 20.0 |
| Wavelength & Retardation | Part No. | Part No. | Part No. | Part No. |
| 1064nm: l & 532nm: l/2 | WPT1110 | WPT1112 | WPT1115 | WPT1120 |
| 532nm: l & 1064nm: l/2 | WPT1210 | WPT1212 | WPT1215 | WPT1220 |
