1/4" Diodes? What are these and how to drive them?

[5v1i5v0]

Both of the diodes(?) are about 1/4" wide. The one that looks like a jumbo LCC says high power on it and I believe it to be IR. How do I power it, and with how much juice? And when powered, would there be a small red light visible, as with regular IRs? Second one has a very large window, through which can be seen; 8 posts (with corresponding solder joints on the PCB), an anode plate, a cathode plate, and 2 micro wires connecting the plates to single post each. What is it, and how do I power it? I posted the 2nd one before, with lousy cell phone pictures, and got a suggestion that it might be a quadrature...but wouldn't a quadrature have 4 sets of connections rather than just 2 connections?

 

[KiLLrB]

looks like a read head from a dvd drive ive seen

 

[bobhaha]

Mind telling us where you got them from?

 

[lasersbee]

The Large Gold one looks like a quadrant detector...
used to center a Laser Beam...IMO


Jerry

 

[5v1i5v0]

The IR diode came from ebay, along with a c-mount and no specs or info. The other one came from the assembly shown in pics 1 & 2. Also on that assembly is the thing in pic 3, any ideas what it is? It looks to have heat damage radiating up from the hole and there is a white mass inside that looks a little like ceramic.