Sjouke Burry s@b wrote in message
2.10...
"N_Cook" wrote in :

For self-education I decided to take apart a presumably defunct DVD
laser unit to see the internal layout of splitters etc and what the
laser diode looks like. Googling in images I only find graphics or
external views, anyone know of a WWW view through the window of some
good laser diodes ?. Looking via x30 at what I assume to be the active
surface is a uniform grey colour and uniform crystalline appearance
rectangular face (ie no obvious hot spot/s) like a finer grained
version of a fractured surface of cast aluminium or monkey metal.
Is this the infamous Catastrophic Optical Damage ?
This one has a marking of RH on the body.






If it is a visible light laser diode, just use a lens to produce
an image of the chip on your wall.
That is safe to look at, and shows the light distribution.


I went the "unsafe " route and put 2.5V and 560R over the 1.6V DVM diode
test junction ( 1.3V of the other pair of pins of this recordable DVD
laser). The dim and dull-red light came from the junction between the grainy
block surface and the pillar . In my one the end of the pillar is a
"polished" surface with no metalisation over it unlike the one in that pic.