Novel Pump Configuration for Thin Disk Lasers

Since its introduction the thin disk laser based on Yb:YAG material has been thoroughly investigated and first industrial systems are now available. Nevertheless, some problems arise when scaling the power up: The pump set-up is becoming complicated and there could be some difficulties in bonding the thin disk on the cooling finger. In this paper, we describe a novel pumping scheme solving those two problems. Instead of pumping from one face or on the side of thin disk we propose to use a combination of both using an additional optical element to guide the pump light to the disk. We show that up to 85 % of pump light can be absorbed by the laser material and the pump distribution can be very homogeneous. FEA calculations show that this configuration is also favourable to a better cooling of disk and reduced deformation in the laser material.