OMG $28,000 for a laser !!!!!!!!
That's enough for a car or down payment on a house rofl
$28,000 is very cheap for a laser of this level. Once you start getting into systems from Coherent or Spectra Physics, the prices shoot through the roof.
To compare to what most people are used to as a quality laser, a Laserwave system, 3W 532nm with 10% RMS stablility costs ~$6000 depending on where you are getting it. Pretty fair price for the money, about $2 a milliwatt. However the beam specs are not the best, 3mm with a divergence of 3mRad. This laser has a M-Squared (Beam quality) of about 5 when it is actually measured, the measurements they give on the datasheet are wrong.
When you look at the Spectra Physics Millennia, for a Millennia IIi with a T20 power supply, the cost is upwards of $85,000. Granted, this has stability of 0.4% RMS. The beam from the unit is 2.3mm with a divergence of less than 0.5mRad. The M-Squared on this unit is guaranteed to be less than 1.1 with 1 being a perfect Gaussian beam.
Additionally, if you look at the failure rate of the lasers, the Spectra Physics unit is far superior. It uses diodes which are designed for long life, and low degradation, my personal Millennia has a power loss of less then 0.2mA/hour at full power. Many of the Chinese units can have rates of several mA/hour. Simply put, the Spectra Physics units don't fail, and if they do, you have a technician at your door within a day. to fix it.
Now, that being said, there is still an application for the chinese systems, it just doesn't belong in the industrial environment.
It is a type of DPSS, instead of using a Nd:YAG, Nd:YVO4, or Nd:YLF, it uses a optically pumped semiconductor as the gain medium. This medium is the same material as in a laser diode, however it is grown and processed in a way allowing it to run with an external cavity and broad emission. The laser uses a etalon within the cavity to tune the wavelength for optimal efficiency and to prevent secondary lines from becoming parricidal to the gain.
