Help? Diode keeps frying but only in the host.

[amars22]

Purchased the Oclaro HL6388MG 250mW 637nm module from DTR's shop with included driver. I thought the first one was DOA after hooking it up in my host and getting nothing. Hooked it up to my bench supply @ 3.8V (single cell input) and got nothing also.

Diode was replaced free of charge, this time I hooked it to the bench supply first and got a nice pleasant output. Wired it into my host, clicked the switch on, it started to ignite and then just died. Back to the bench supply and nothing again. Interestingly enough the driver still shows it is drawing about 600mA when "on". My question is what could cause this in the host?

The host is from member Lifetime, and I have verified with my probe that there are no shorts in the host. I have checked and double-checked the polarity. My only thought is that there is a ground loop as the diode case/pill is grounded directly to the host as well as the negative wire being attached to the host, but I didn't think a ground loop would cause a laser diode to burn out.

Any ideas or help is appreciated, as I'd really like to figure this out before I blow cash on another diode.

 

[gazer101]

Probably a short circuit somewhere in there, happened to me before... triple check your connections, set your driver to a lower output, and test on a cheapo diode before hooking it up for real

 

[farbe2]

600mA seems a little much, the diode only needs 430mA. If your driver is a Buck type (using the diode with 1 or 2 18650 cells), the current on the input should be much lower, actually around 1/2 for one 18650 cell (215mA).
If you use a boost type driver, you cant use more than one AA cell (1,5V) and the current should be around 700mA on the input.
If you use more than 2,3V on the input of a boost driver (for this diode), current regulation is not guarantied = blowing the diode.

Its best to measure the output not input current.

The diode is also case negative, so your host and driver need to support this.