Bauteile für schwache Nd:YAG oder Nd:YVO4 Laser

Neodymium doped crystals show laser transitions at different wavelengths. Table 1 gives an overview about the laser wavelengths of the most common Nd doped materials Nd:YAG and Nd:YVO4.

Nd:YAGNd:YVO4
Laser lineSecond harmonicLaser linesSecond harmonic
946 nm473 nm915 nm457 nm
1064 nm532 nm1064 nm532 nm
1123 nm561 nm
1319 nm659 nm1340 nm670 nm
Table 1:Laser lines and corresponding wavelengths of the second harmonic of Nd:YAG and Nd:YVO4

As can be seen, a variety of laser lines in the VIS and NIR can be obtained from these crystals. This phenomenon is used to build compact diode pumped solid stated lasers with a variety of wavelengths which are used for measurement applications as well as for projection systems (RGB lasers).

The strongest laser transition in both materials is the 1064nm line. Efficient laser radiation at the other wavelengths is only possible by suppressing this line. LAYERTEC offers a variety of laser mirrors for this application.

Compact laser designs include also the pump diode (808nm) and a unit for the second harmonic generation. This is the reason, why coatings for Nd:YAG or Nd:YVO4 wavelengths apart from 1064nm mostly show several spectral regions of high transmission as well as of high reflection. In the following we present some examples of such coatings. All coatings are designed according to customer specifications, because the specifications depend on the laser design. All examples on these pages are for Nd:YAG wavelengths. Coatings for Nd:YVO4 can be designed and produced as well.


FeatureReflectivity
Suppression of the strongest laser lineR(0°, 1064 nm) < 5 %
HR mirror for the weak laser lineR(0°, 946 nm) > 99.95 %
Higher transmission for the pump wavelengthR(0°, 808 nm) < 2 %
HR mirror for the second harmonic of the weak laser lineHR(0°, 473 nm) > 99.85 %
dual wavelength mirror for a weak laser lineFigure 1: Reflectance spectrum of a dual wavelength mirror for a weak laser line and its second harmonic with high transmission for the pump wavelength and the strongest laser line:
HR(0°, 473nm) > 99.85% + HR(0°, 946nm) > 99.95% + R(0°, 808nm) < 2% + R(0°, 1064nm) < 5%

FeatureReflectivity
HR mirror for the weak laser lineHR(0°, 1123 nm) > 99.9 %
Suppression of the strongest laser lineR(0°, 1064 nm) < 50 %
High transmission for the pump wavelengthR(0°, 808 nm) < 10 %
High transmission for the second harmonic of the weak laser lineR(0°, 561 nm) < 2 %
dual wavelength mirror for a weak laser lineFigure 2: Reflectance spectrum of a dichroic mirror with high transmission for the pump wavelength which also suppresses the 1064nm line:
HR(0°, 1123nm) > 99.9% + R(0°, 561nm) < 2% + R(0°, 808nm) < 10% + R(0°, 1064nm) < 50%

FeatureReflectivity
HR for s-polarized light of the weak laser lineHRs(56°, 1123 nm) > 99.9 %
Suppression of p-polarized light of the weak laser lineRp(56°, 1123 nm) < 50 %
Suppression of the strongest laser lineRs + p(56°, 1064 nm) < 50 %
High transmission for the pump wavelengthRs + p(56°, 808 nm) < 10 %
High transmission for the second harmonic of the weak laser lineRs + p(56°, 561 nm) < 10 %
thin film polarizerFigure 3: Reflectance spectra of a thin film polarizer with high transmission for the pump wavelength and the second harmonic which also suppresses the 1064nm line:
HRs(56°, 1123nm) > 99.9% + Rp(56°, 1123nm) < 50% + Rs,p (56°, 561+808nm) < 10% + Rs,p(56°,1064nm) < 50%

FeatureReflectivity
Broadband HR mirror for several laser lines HR(0°, 1064 + 1123 + 1319 nm) > 99.9 %
High transmission for the second harmonics of these laser linesR(0°, 532 - 561 + 659 nm) < 2 %
thin film polarizerFigure 4: Reflectance spectrum of a dichroic mirror with high reflectance for the NIR wavelengths and high transmission for the corresponding second harmonic wavelengths:
HR(0°, 1064 + 1123 + 1319nm) > 99.9% + R(0°, 532–561+659nm) < 2%