Components for higher harmonic of Ti:Sapphire laser
Components for the Higher Harmonic of Ti:Sapphire Laser
The fourth and fifth harmonics of the Ti:Sapphire laser provide fs-pulses in the DUV / VUV range. These offer a variety of applications in spectroscopy as well as in materials science. Optics for these very special applications must be optimized for high reflectivity and low dispersion.
Turning Mirrors and Separators for the Fourth Harmonic
Figure 1: Reflectance (measured, a) and GDD - spectra (calculated, b) of a turning mirror for 200nm (AOI = 45°)
Figure 2: Reflectance (a) and GDD - spectra (b) of a separator for the fourth harmonic from the longer wavelength harmonics and the ground wavelength (AOI = 45°)Components for the Fifth Harmonic
Figure 3: Reflectance (measured, a) and GDD - spectra (calculated, b) of a turning mirror for 160nm (AOI = 45°)Special Components
Figure 4: Reflectance (a) and GDD - spectra (b) of a separator with high reflectivity in a small wavelength range in the VIS and high transmission for the third and fourth harmonics of the Ti:Sapphire laser:
HRs(45°, 420nm) > 99% + Rp(45°, 200 + 270nm) < 3% Properties of Femtosecond UV Coatings
- Depending on the wavelength range of the fundamental wave, the coatings described on this page, as well as the components for the third harmonic of the Ti:Sapphire laser, can be used for the following central wavelengths:
- Third harmonic: 250 – 330 nm
- Fourth harmonic: 180 – 250 nm
- Fifth harmonic: 150 – 180 nm
- Bandwidths of the coatings are given in the table below
- Coatings are optimized for broad reflection bands, high reflectivity and low GDD
- Different substrate and coating materials depending on the wavelength range; components for 220 nm and below consist of fluoridic layer systems on CaF2 - substrates
Bandwidth of the High Reflectance and Low GDD range | Component | Wavelength range | P-polarization | S-polarization |
|---|
| R > 99 %, |GDD| < 20 fs2 | R > 99. 5%, |GDD| < 20 fs2 |
|---|
| Turning mirror 3rd harmonic | UV | 30 nm | 50 nm |
| Separator 3rd harmonic | UV | 30 nm | 50 nm |
| Dual wavelength turning mirror | UV | 15 nm | 26 nm |
| UV / VIS | 34 nm | 72 nm |
| Turning mirror 4th harmonic | UV | 5 nm (R > 93 %) | 15 nm (R > 97 %) |
| Turning mirror 5th harmonic | UV | 4 nm (R > 90 %) | 12 nm (R > 97 %) |
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