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Entry  Thu Feb 18 08:12:53 2016, KojiN, Misc, PD QE, Re-measurement of the reflectivities and the EQEs of the PD for S-pol and P-pol QE3.pdfQE_ll.pdf
    Reply  Thu Feb 18 13:39:33 2016, Koji, Misc, PD QE, Re-measurement of the reflectivities and the EQEs of the PD for S-pol and P-pol 
       Reply  Fri Feb 19 00:01:36 2016, KojiN, Misc, PD QE, Re-measurement of the reflectivities and the EQEs of the PD for S-pol and P-pol 6x
Message ID: 2020     Entry time: Thu Feb 18 08:12:53 2016     Reply to this: 2021
Author: KojiN 
Type: Misc 
Category: PD QE 
Subject: Re-measurement of the reflectivities and the EQEs of the PD for S-pol and P-pol 

The reflecrivities and the EQEs of the PD (C30665GH, with the glass window) for S-pol and P-pol were measured at every 10 deg in incident angle as shown in Fig. 1 and Fig. 2.

In this measurement, for alignmnet the steering mirror was used and it was confirmed that the beam was not clipped.

The EQE is obtained from the DC output voltage which was read from the oscilloscope using the following equation (see also elog2019):

{\rm EQE} = \frac{I_{\rm PD}hc}{\phi ne\lambda} = 5.32 \times 10^{-3} \left( \frac{V_{\rm out}}{1 {\rm V}} \right) \left( \frac{1{\rm W}}{\phi} \right),

where I_PD is the photocurrent, V_out is the DC output voltage, h is Planck's constant, c is the speed of light, phi is the incident power, n is the index of refraction of air, e is the elementary electronic charge, and lambda is the wavelength of the laser.

Fig. 1 Measured reflectivities for P-pol and S-pol.
Fig. 2 Determined EQEs for P-pol and S-pol.

 

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