Overboosted 5mw laser?

I just bought a cheapo greenie off ebay for $5 and it is rated at 5mW. However, it is extremely bright and somewhat compares to my Dragon Laser 532nm - 200mW or my Wicked Laser 532nm on low power...but only for about 10 seconds. My guess is that it's briefly at over 50mW, then power drops considerably after that 10 seconds. I can clearly see the Rayleigh effect during this short time in a lighted house at night. Is the power dropoff a result of the diode overheating? If so, is there anything I can do to increase the "duty cycle"?

It probably has no heat sink or a very skimpy one. If there is room you can replace it or add on a beefy copper heat sink.

Adding a heatsink may improve it, it may not. Could be that the diode or the crystals aren't being cooled effectively - or even both. There are lots of factors that affect output with DPSS.

Depending on what you have it wouldn't hurt to try adding a better heatsink - though for a 5$ laser, is it worth it?