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Entry  Mon Sep 23 10:49:27 2019, Koji, Summary, PD QE, QE and dark current of InAsSb sensors InAsSb_QE.pdfInAsSb_DarkCurrent.pdf190921_SbPD_QE.zip
    Reply  Wed Sep 25 01:05:30 2019, Koji, Summary, PD QE, QE and dark current of InAsSb sensors P_20190924_233507_vHDR_On.jpgP_20190925_003614_vHDR_On.jpgInAsSb_QE.pdfInAsSb_DarkCurrent.pdf
       Reply  Thu Dec 5 13:50:59 2019, Koji, Summary, PD QE, Dark current measurement with the sourcemeter InAsSb_DarkCurrent_markedup.pdf
Message ID: 2425     Entry time: Wed Sep 25 01:05:30 2019     In reply to: 2423     Reply to this: 2468
Author: Koji 
Type: Summary 
Category: PD QE 
Subject: QE and dark current of InAsSb sensors 

The lenses were arranged so that the spot on the PD can become smaller. A quick measurement on a (500um)^2 element showed the QE of ~80%

With the strong focusing lens of f=40mm, the beam was once expanded to a few mm. Then f=75mm lens focuses the beam to ~30um (radius). (See Attachments 1&2)

With this new beam, the QE was quickly checked. The new measurement is indicated as "Sb3513 A2P6new" in the plot. It showed the QE of ~80%.
The AOI was scanned to find any maximum, but the AOI of 0deg was the best at least with the given beam. I'm not sure yet why 500umx500um requires such small beam radius like 30um. Awesome

Attachment 1: P_20190924_233507_vHDR_On.jpg  822 kB  Uploaded Wed Sep 25 02:12:16 2019  | Hide | Hide all
P_20190924_233507_vHDR_On.jpg
Attachment 2: P_20190925_003614_vHDR_On.jpg  2.095 MB  Uploaded Wed Sep 25 02:12:16 2019  | Hide | Hide all
P_20190925_003614_vHDR_On.jpg
Attachment 3: InAsSb_QE.pdf  139 kB  Uploaded Wed Sep 25 02:13:49 2019  | Hide | Hide all
InAsSb_QE.pdf
Attachment 4: InAsSb_DarkCurrent.pdf  142 kB  Uploaded Wed Sep 25 02:14:01 2019  | Hide | Hide all
InAsSb_DarkCurrent.pdf
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