- Laser Guide Star for adaptive optics systems
- Excitation of atmospheric Sodium @ 589nm
- > 20W cw output power, linewidth < 5 MHz
- 2 W version available for laser cooling of Sodium
The SodiumStar system is a high-power “guide star” laser designed for adaptive optics control in ground-based telescopes. It is based on resonant frequency doubling of an infrared DFB diode laser with subsequent Raman fiber amplifier. More than 20 W are attained at the Sodium wavelength of 589 nm, with a spectral width of 5 MHz. The DL RFA SHG pro, a modified, sub MHz linewidth version with moderate power (2 W) is available for laser cooling experiments.
Schematic setup of TOPTICA’s SodiumStar guide star laser.
Output power of TOPTICA’s SodiumStar laser, as a function of fundamental (infrared) power. Resonant frequency conversion is achieved with an efficiency in excess of 75 %.
|Seed laser||DL DFB|
|Amplifier||Raman fiber amplifier|
|Doubling stage||SHG pro|
|Tuning||> 10 GHz|
|Linewidth||˜ 5 MHz|
|Output power||> 20 W|
|Spatial mode||Near diffraction limited|
|Optical isolation||Included, 60 dB + 35 dB (before / after amplifier)|
|Water cooling||Yes (for amplifier stage)|
|Operating voltage||220 .. 240 V AC, 50 Hz|
|Power consumption||1.3 kW max.|
Options & Related Products
Options & Related Products
- TA-SHG pro System for Sodium cooling (1 W, 1 MHz linewidth, completely semiconductor based)
- System for Sodium laser cooling (2 W, 1 MHz linewidth): DL RFA SHG pro
- Low-power frequency-converted diode laser: DL SHG pro
- Tunable deep-UV laser: TA / FA FHG pro
- Control and locking electronics: DigiLock 110, FALC 110, PID 110, PDD 110/dual
- Photonicals: Laboratory tools and accessories, e.g. Fabry-Perot Interferometers and Wavelength Meters, …
|Guide Star laser in operation at the Very Large Telescope on Cerro Paranal, Chile. The LGS excites the Sodium atoms which are present in the mesosphere, 90 to 110 km above the Earth’s surface and creates an "artificial star".|
|Adaptive optics systems correct wavefront aberrations (top row) caused by atmospheric distortions, rendering the images of stars point-like (bottom row).|
Reaching for the stars, (Laser+Photonics - Made in Germany, Austra & Swizerland 2011, p.28)
Laser Guide Star Facility Upgrade (S. Lewis et al., Messenger No. 155 (March 2014)
Y. Feng et al., 25 W Raman-fiber-amplifier-based 589 nm laser for laser guide star; Opt. Express 17:21 (2009) 19021.
Guide Star Laser for VLT: Tilt Test
Guide Star laser for adaptive optics system at the Very Large Telescope (VLT) at Paranal, chile.Challenges for laser operation: altitude, earthquake-resistant design and gravity-invariant operation. TOPTICA's guide star laser delivers a constant oupot power of 22 W at 589 nm.