From Kevin Tice
Omnichrome
 
Additional information regarding laser lifetime:
 
The lifetime of a laser is dermined by many factors; the alignment of the
resonator mirrors, the amount of tube current driving the plasma,
contamination to optical surfaces, etc all have an effect on life time.
 
The mirror alignment is very important because it affects: 1) the amount of
tube current being supplied to the laser - if in light feedback control or 2)
the output power of the laser - if it is  operating in current control.
 
In case 1), if the mirrors are out of alignment the only thing the laser can
due to maintain the desired/set power level is to increase the tube current
to compensate.  This in-turn lowers the lifetime of a laser.
 
In case 2), if the mirrors are out of alignment the output power of the laser
will drop and the user will have to increase the tube current manually by incr
easing the power level adjust to achieve the previously set power level.
Since, there is now a higher tube current level, the life time of the laser
is shortened.
 
These are the most likely cases for premature laser failure, i.e. mirror
alignment.  The other thing to look at would be the laser, to see if the
product is correct for the application.
 
The ILT laser produces 4 to 5mW per primary line (488, 568, 647nm) and runs
at a high tube current to get this power - standard physics.  Therefore it
this laser is running at 8 to 9.5Amps most of the time then you should only
expect to see 500 to 1000 hours of life.  At the same token, if the laser is
operated at 5 to 6Amps then you should expect 1500 to 2500, but the power
level will most likey to low for use in the application.
 
There are other products on the market that produce a higher output power,
15+mW per primary line (488, 568 and 647nm) that if operated at low tube
currents i.e. 5 to 7Amps, would produce the desired 5mW output power.  With
such a low initial tube current, this laser should last 1500 to 2500 hours.
 The unit price is about the if not less than the 5mW laser.  The only down
side is it is a little larger and runs on 190 to 240VAC @ 20A single phase.
 But in terms of price/performance per milliwatt it is well worth it.
 
If anyone has any questions regarding lasers (of any type), optical noise,
laser beam optics, etc. Please feel free to e-mail me directly at [log in to unmask]
om
 
Thanks
 
Kevin B. Tice
Applications Engineer
Product Specialist
Omnichrome Corp.