Unfortunately, the opposite is true: when you turn on laser is not leaking more current compared to its normal operation. Ie a small glow of - it's still a resource reduction diode, rather than an increase.
And any more quickly assess the discs it does not promote!
Infrared laser (for reading CD) - yes, this is possible because his range beyond the visible to the human eye, but the usual red laser (for reading DVD) see eye just as blue. Therefore, this assumption is also unlikely to correct.
I asked this same question in a forum for repair, where a few people said to me that other BD-drives blue light when operating without disk is missing.