Switching laser diode ON/OFF

Hi,
 
   I want to know if what I had done is fine.  First I will explain  I need to switch on/off my laser diode at aprox 10khz.  I had build a current regulator with a LM317 and the other side of the diode I use a transistor to switch on/off.  On the O-Scope it's OK but is it bad to switch power on/off  may I switch below the triger point not a 0V?

You can check my electronic schematic at: www microsyl com / laser.pdf
Thanks for your time
Sylvain Bissonnette

people do it all the time, it works fine.

http://www.rp-photonics.com/gain_switching.html