I guess, this is due to a very strong difference between the laser pulse duration (10-100ns) and the temporal characteristics of the IR thermometer (10-1000ms). The IR thermometer won't be able to capture a rapid temperature jump, so the only use of it will be the monitoring of average temperature, which is, probably, far less interesting in this case (I'm not a specialist in skin resurfacing, but I suspect that one needs to control the peak of energy absorption).

Dear Artem,

Thank you for your fruitful answer :)

I strongly agree the IR thermometer cannot do instantaneous response to typical ns laser pulse. I found some laser specifications for skin resurfacing and they use sub-ms to ms pulse width, which intentionally extend the pulse width.

https://quantausa.com/products/evo-light-series/#Specifications

https://syneron-candela.com/hk/product/4837/system_specifications#6105

https://medsharelaser.com/product/cooltouch-ct3/

https://www.almalasers.com/alma-products/alma-q/

I also found some academic research used IR camera or pyrometer for the temperature monitoring (of course, this case only detects epidermis temperature).

I think that implementing the thermometer system to laser equipment can provide some availability to physicians even though the temperature reading is not that accurate, and I wonder why almost all current systems don't.

Anyway, thank you for your awesome opinion :)

OK, if it is in the millisecond domain, then it's easier - the only problem will be to synchronize the readings with the laser pulse (if not then each time the IR detector will measure a different part of the "tail", and the readings won't be stable).