Transmission tolerances | ±2 % |
Surface flatness | <λ/10 @ 632.8 nm |
Diameter tolerances | +0.0 / -0.2 mm |
Parallelism error | < 20 arcsec |
Perpendicularity | < 5 arcmin |
Surface quality | 10-5 scratch & dig (per MIL-O-13830A) |
Protective chamfers | <0.1 mm @ 45° |
AR Coating reflectivity | <0.2 % @ 1540 nm |
|
Co2+:MgAl2O4 | Cr4+:YAG |
Working wavelength range, µm
|
1.2-1.6 | 0.8–1.2 |
Ground state absorption cross-section, cm2
|
3.5×10-19 (at 1.54 µm) |
5×10-18 (at 1.06 µm) |
Initial transmittance, %
|
30-99 | 20-99 |
EKSMA Optics Passive Q-Switching Crystals
85.65 kB |
Co2+:MgAl2O4 (Co:Spinel or Co:MALO) is a relatively new material for passive Q-switching in lasers emitting from 1.2 to 1.6 µm, in particular, for eye-safe 1.54 µm Er:glass laser, but also works at 1.44 µm and 1.34 µm wavelengths.
High absorption cross section (3.5 × 10-19 cm2) permits Q-switching of Er:glass laser without intracavity focusing both with flash-lamp and diode-laser pumping.
Negligible excited-state absorption results in high contrast of Q-switch, i.e. the ratio of initial (small signal) to saturated absorption is higher than 10.