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Active surface of a laser diode?

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.

Reply to
N_Cook
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So if the active surface of this pic , (different internals to the one I have looked at )

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is the uppper part of the die then the same grey granular appearance

Reply to
N_Cook

Den 01-04-2013 13:56, N_Cook skrev:

How about the small 'rod' that the 4 bonding wires from the right pin goes on top of?

--
Uffe
Reply to
Uffe Bærentsen

9b.jpg

I think the laser diode is the long gold bar with four wires going to it. I'm not sure what the silver cube next to it is.. a temerature sensor?

The whole thing is on some substrate.. maybe Alumina or Silicon??

The emitting area of a laser diode is really tiny.

George H.

Reply to
George Herold

The "active surface" is a channel through the die, there's a tiny aperture in the middle of that "granular surface".

Reply to
Ian Field

Smaller than the resolution of that photo or the small blackish rectangle on the end of the "bar" that ends flush with the granular surface, on a line between the centres of the end faces of the conductor pins. Dimensions of that rectangle about one of those wires diameter x about 4 wire diameters

Reply to
N_Cook

There are various laser tutorials online with exploded view representations of the junction structure - that's where I got all I have.

Reply to
Ian Field

"N_Cook" wrote in news:kjbreu$8ds$ snipped-for-privacy@dont-email.me:

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.

Reply to
Sjouke Burry

Sam would likely know. Nice picture.

-- Cheers, WB .............

Reply to
Wild_Bill

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.

Reply to
N_Cook

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