40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Entry  Thu Oct 7 14:39:50 2010, yuta, Update, PSL, measured PMC's laser power-output relation PMCreflect.png
    Reply  Thu Oct 7 15:05:46 2010, Koji, Update, PSL, measured PMC's laser power-output relation 
       Reply  Thu Oct 7 16:34:06 2010, yuta, Update, PSL, measured PMC's laser power-output relation PMCvis.png
          Reply  Thu Oct 14 12:53:29 2010, yuta, Update, PSL, mesured PMC's visibility vs power relation PMCsetup.pngPDcalib.pngPMCreflect2.png
Message ID: 3672     Entry time: Thu Oct 7 16:34:06 2010     In reply to: 3669     Reply to this: 3717
Author: yuta 
Type: Update 
Category: PSL 
Subject: measured PMC's laser power-output relation 

Result2:
 Attached is the visibility vs incident power(assuming output of the PD is proportional to the input laser power).
 Ideally, the graph should be flat. (In another words, attached graph in the elog #3667 shoud be linear.)
 But the visibility reduces with higher laser power in this graph. This is maybe because of the thermal effect. I'm thinking about how to confirm this.

 Quote:

It was a bit difficult to comprehend the result.
Is it good? or bad? Have you seen the thermal effect? or not?

- Put linear lines to show the visibility of the cavity.

- Calibrate the incident power and make another plot to show the visibility (%) vs the incident power (W).

Quote:

(Rana, Yuta)

Motivation:

 We wanted to see thermal effects on the PMC.

What I did yesterday:
 Changed the current of the NPRO from 2A to 0.8A and measured the power of the reflected/transmitted light from the PMC when locked.
 I also measured the power of the reflected light when PMC is not locked (It supposed to be proportional to the output power of the laser).

Result:
 Attached. Hmmmm......
 At several points of the laser current, I could'nt lock the PMC very well. The power of the reflected/transmitted light depend on the offset voltage of the PZT.
 When the laser power was weak(~<0.9A), the power of reflected/transmitted light changed periodically(~ several minutes).

 

 

Attachment 1: PMCvis.png  25 kB  | Hide | Hide all
PMCvis.png
ELOG V3.1.3-