red laser is polarized?

[Robk]

I put together a DVD writer diode, Aixiz brass holder and a constant current power supply (LM317) like most everyone here has. The momentary button supplies 200mA to the diode, the slide switch provides 100mA for aligning, longer running, etc., when I don't need to burn something. Works great, focus dial is the old volume control knob from a CD player drilled out. My question is how come the output is polarized? If I put a camera polarizing filter in the beam and rotate it, it almost goes out! I remember the old days with HeNe lasers, sometimes there was an internal mirror set at "brewster's angle" to polarize the beam. Does anyone know what plane these diodes are polarized at, in other words, what angle in relation to the three leads on the back? Theoretically, if it was known, a cheap pair of polarized sunglasses may act as protective eyewear if the diode was rotated in the housing properly. Any ideas?
Rob

 

[pseudonomen137]

I think it would change from diode to diode. Don't try getting away with sunglasses as a protective method though. Normally "polarized" sunglasses are circularly polarized, aren't they? If that's the case, they wouldn't really help much. Even with linear polarization, its not going to be perfect and you'll still let a potentially dangerous amount of light through (not the mention a focused DVD diode could probably burn through the polarization)