I have just built a 1 Watt blue laser, however, I am not happy with the resultant beam. The beam is approximately 1mm wide x 5mm high. I want to focus this down to less than 1mm square. What lens do I require for this?
The 445nm diodes have a rectangular looking beam, even when focused tight. 405nm however can get very small to a pen point almost.The lens you received may not be glass. Where did you buy your laser? If you dont mind me asking.
I bought it on Ebay, from O-like shop. these are the specs:
Part No OL-445-1W
Wavelength 445-450nm
Output Power >800mW
Input Voltage 12VDC
Input Current 2A
Operating Temperature 0℃-30℃
Working Mode 0-20KHZ
Divergence <3.0mrad
Lens Material Glass
Operating Lifetime >5000Hrs
Wire long 300mm
Size laser module :66x33x33 mm
power supply :68x43.50x36mm