tec laser diode cooling
The challenge to get Qmax is to have an infinite heatsink attached to the Peltier junction. 

If good thermal resistance and high velocity 35mm fan air over heatsink to push heat away then 15x15 mm size may do with Rja &lt;=1'C/W  or 10'C T rise with 10W while a CPU heatsink &amp; fan &lt;0.1'C/W

Qmax: 3.4 W 
Delta Tmax: + 87 C 
Maximum Current: 2.1 A 
Maximum Voltage: 3.8 V   (means 8 Watts applied plus W Laser  9 W)
Length: 15 mm 
Width: 15 mm