Here is the report of the laser characterization for the cavity experiment (effect of birefringence on alignment strategy of crystalline cavity)

-Laser nominal specification :

reference : LightWave 126-1064-500

serial number : 204

Manufactured date : July 1994

Maximum power : 2W

-Control specification: 

name : LightWave 125/126

serial number : L-7-2001-6

First the relation between the electric intensity provided by the controler and the optical power at the output of the laser has been characterized. The data and the linear fit made with a least square method can be found on the figure 1. The measurent has been done at 26cm from the laser aperture without optical layout between both.

Then we installed a half wavelength plate and a beam sampler in order to controle the power that will be injected in the future optical system. The first optics are know installed, the actual setup can be seen on the figure 2

From this setup, we measured the beam radius as a function of the postion from the lens. The lens is used to focus the beam as the beam radius was too large for the beam profiler aperture, its focal lens is 100mm. Simulation work will be necessary to recover the real beam radius from the laser aperture and will presented in a future logbook or as a reply of this one. The beam radius as a function of the distance from the lens can be seen on the figure 3. The measurement has been done for two radius in two orthogonal directions. The parameter found are :

For Ww(d)

w0 = 263.72 ± 32.54 um

z0 = 11.51 ± 0.08 cm

zr = 1.29 ± 0.18 cm 

For Wv(d)

w0 = 278.19 ± 2.68 um

z0 = 11.86 ± 0.09 cm

zr = 1.03 ± 0.19 cm

With Ww and Wv the beam radius in two orthogonal direction keping the notation used by the beam profiler software.