Components for Nd:YAG / Nd:YVO4 Lasers
Mirrors and Partial Reflectors
- HR cavity and turning mirrors with R > 99.9 % at AOI = 0° and at AOI = 45° for s- and p-polarized light
- Typical reflectivity: R > 99.95 %
- For special demands we guarantee R > 99.99% (delivery with cavity ring down measurement)
- Spectral bandwidth of about 70 nm, 1-on-1 LIDT > 50 MW/cm2 (cw) and > 50 J/cm2 (10 ns)
Figure 1: Reflectance spectra of a high power cavity mirror (a) and of output couplers with different degrees of reflectivity (b) Beam Splitters and Output Couplers with precisely adjusted degree of Reflectivity
Figure 2: Reflectance spectra of a pilot mirror HR(1064 nm) + PR(630 – 670 nm) for s-, p- and random polarization at AOI = 45° (a) and for random polarization at different AOI (for use as scanning mirror) (b) Reflectance | Tolerance |
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R > 95 % | ± 0.5 % |
R = 80 ... 95 % | ± 1 % |
R = 10 ... 80 % | ± 2 % |
- Pump mirrors HR(0°, 1064 nm) > 99.9 % + R(0°, 808 nm) < 2 %
- Beamsplitters, beamcombiners and scanning mirrors
- Optics for the harmonics of the Nd:YAG / Nd:YVO4 laser are presented at our sites 2nd-harmonics, 3rd-harmonics and higher-harmonics
Thin Film Polarizers
- Separation of the s- and p-polarized component of the light (s-polarized light is reflected and p-polarized light is transmitted)
- TFPs can be produced for AOI > 40°, but polarization is most efficient and appears in a broad wavelength range if AOI ≈ 55° (Brewster angle) is used
- Typical polarization ratio: Tp/Ts > 500 for AOI = 45° or 55°
- Special designs with a polarization ratio of Tp/Ts up to 10000 are possible
- High laser damage thresholds (useful for intra cavity applications
- The transmission of thin film polarizers for p-polarized light can be measured with high accuracy by a modified cavity ring down setup
Figure 3: Reflectance spectra of a pilot mirror HR(1064 nm) + PR(630 – 670 nm) for s-, p- and random polarization at AOI = 45° (a) and for random polarization at different AOI (for use as scanning mirror) (b) Nonpolarizing Beam Splitters
- Beamsplitters with Rs ∼ Rp(|Rs – Rp| < 1.5 %) for AOI = 45° and different degrees of reflectivity
- Most common types:
- Rs,p = 66 ± 1 %
- Rs,p = 50 ± 2 %
- Rs,p = 33 ± 3 %
- All nonpolarizing beamsplitters with rear side AR(Rs ∼ Rp ≤ 0.6 %)
Figure 4: Reflectance spectra of 3 types of nonpolarizing beam splitters (AOI = 45°)