Here is the graph from Mike for the Stenkat 808nm 200mW diode
"I ran this diode later at 400 mA (270 mW) for a life test."
I made some research about the optical conversion efficiency of
808@1064 with Nd:YVO4 and
1064@532 with KTP.
(from Casix)Recently, over 30 W of TEM00 output power was achieved by using a-cut Nd:YVO4 and pumped by 60 W fiber coupled diode lasers. The optical conversion efficiency exceeds 50%.High power and stable infrared output @ 1064 nm and 1342 nm has been available with diode pumped Nd:YVO4 lasers.
Potassium Titanium Oxide Phosphate (KTiOPO4 ), or KTP, is an efficient nonlinear optical crystal in the visible to infrared spectral region with relatively low cost. It has large nonlinear coefficient. The effective nonlinear optical coefficient of KTP deff at 1064nm is more than 1.5 times that of BBO. It's damage threshold is near 1 GW/cm2 for 1 Hz 10 ns pulses at 1064nm. However, it is now limited to moderate to low power applications due to it's gray-tracking problem.
[FONT=verdana,helvetica,arial,geneva]
Advantage[/FONT]
- [FONT=verdana,helvetica,arial,geneva]Efficient frequency conversion(1064nm SHG conversion efficiency is about 80%)[/FONT]
These conversion efficiency can drop dramatically if the temperature is not controled. So 50% for Nd:YVO4 and 80% for KTP can be obtained for moderate temperature.
We know that olike module can do 140 mw(120-150mw version) of pure 532 nm with a 350 mA current.
i'm supposing that the pump diode in the olike module is the same than the Stenkat one, so at 350 mA, the graph of Mike say that the output of the diode is nearly
236 mw.
Supposing that the Efficiency is for both crystal 50% & 80%, i obtain an output power of 532 nm at 95 mW... which is far from the reality (about 140 mW).
1)It can't be the same diode as stenkat.
We obtain 140 mw of 532 nm. With both 50/80 efficiency for crystal, this tends to have a pump power of 808 nm at 350 mW .
i see on others websites that some 200 mw diode, if extrapoled can do 300 mW at 350 mA as .3lite say, or exactly at 370 mA (
http://www.uocnet.com/pdf/LD/U-LD-80C044D-preliminary.pdf)
So 350 mW is a little too much, it seems to be 300 mW pump diode. The only explanation is that the efficiency of Nd:YVO4 is higher than 50 %. As the pump power is a "low power" compared to the 60W pump of casix, the efficiency could be higher than 50%, i guess 60%.
With a 300 mw diode and efficiency of both crystal at 60/80, it give an output of 144mW of pure 532 nm.
im a little surprised. I have always thought that the conversion efficiency was 35/40. Was wrong.
So this little module are great.
