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Message ID: 2030     Entry time: Mon Feb 22 23:51:18 2016
Author: KojiN 
Type: Misc 
Category: PD QE 
Subject: Beam shape reflected by the PD 

The beam shape reflected by the PD was measured.

The measurement was done 5 cm and 15 cm far from the PD at 15 deg, 45 deg, and 60 deg in incident angle.

(Please note that only at 15 deg, the measurement was done at 5 cm because of the space constraint.)

The results are shown in Figs. 1 and 2 and Tabs. 1 and 2.

When Figs. 1 and 2 are observed, the beam shape reflected by the PD looks still gaussian.

In the simulation, the beam size is estimated as, at 5 cm, 403 um in x-direction and 391 um in y-direction and, at 15 cm, 792 um in x-direction and 766 um in y-direction, respectively.

When Tabs. 1 and 2 are observed, the measured beam size looks not so different from the simulated one.

Fig. 1 Screen of the CCD camera at 15 deg and 15 cm.
Fig. 2 Screen of the CCD camera at 45 deg and 15 cm.

Tab. 1 Beam size in x-direction

  15 deg 45 deg 60 deg
5 cm (6 cm) 470 um 406 um 411 um
15 cm 736 um 625 um 608 um

 

Tab. 2 Beam size in y-direciton

  15 deg 45 deg 60 deg
5 cm (6 cm) 522 um 489 um 491 um
15 cm 815 um 811 um 760 um

 

Attachment 1: BeamAt15deg15cm.pdf  917 kB  | Hide | Hide all
BeamAt15deg15cm.pdf
Attachment 2: BeamAt45deg15cm.pdf  1.045 MB  | Hide | Hide all
BeamAt45deg15cm.pdf
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