Comment to T70#3 (Click here to view original report: 3514)

edges at 48.5 and 79 mm : z_center = 63.75 mm

map at z_center : Thu, Apr 4, 2024 2-23-48 PM.txt

T70#3

I installed the 30mm diameter; 70mm length, 4/6 sapphire (T70#3) with pink tape at bottom towards IU.

Realigned DC

Pt = 26.3mW ; Pin = 30.7 mW

Pt = 4.87W ; long z scan (as for all previous z scan at x,y center ie 327,119 mm) : Thu, Apr 4, 2024 11-59-20 AM.txt

Comment to t70#2 (Click here to view original report: 3509)

z = 66.5mm, Pt = 4.83W : Wed, Apr 3, 2024 9-59-53 PM.txt

Comment to tidying up electronics (Click here to view original report: 3508)

I swapped the R and L cables for the OPO mixer.

During this process a cable for CC PLL monitor was quite damagedd but it's a bit tedious to replace alone and not priority for now so I left it as is for now.

I finalized the new box connections and little cable tidy up.

I could lock SHG after changing the DDS1 DAC1 phase from 20 to 240deg and the servo gain from 0.9 to 0.1 to avoid ringing. I measured about 30% HOM still present and 235mW of green produced.

The MZ/GRMC are heavily misaligned and I'll recover them tomorrow.

Manipulation 2D polarization

I choose and align two different lenses in order to extend my initial beam : - 1 inch ; f=25.4mm . - 2 inches ; f=750mm.

I've installed my two supports, made using a 3D printer, for the LCD (from the screen of a monitor).

The beam of the setup is too low to path throw the LCD screen. So I added to more mirrors (2 inches) to get the beam higher, and I started to align them.

Comment to t70#2 (Click here to view original report: 3509)

z = 46.5m, Pt = 4.73W : Wed, Apr 3, 2024 5-28-27 PM.txt

t70#2

Installed T70#2 (30; 70 mm 5/6)

pink tape at bottom towardsiu

realigned DC

Pt = 27.4mW ; Pin = 31.5mW

long z scan Pt = 4.77W ; Wed, Apr 3, 2024 12-31-34 PM.txt

z edges at 36 and 77 mm : z_center = 56.5 mm

map at z_center : Wed, Apr 3, 2024 1-11-48 PM.txt

tidying up electronics

I finalized the mixers box and installed it in the bottom NIM rack.

A little issue is that the BNC mixers are a bit too large to close the box... However we still have quite some space in the NIM racks so I'll leave the box open for now.

I'm also taking this opportunity to change cables for more appropriate ones and passing them through the cable clamp.

One thing I'm not sure about is that OPO RF signal was sent to the 'L' port of one mixer which I thought was for LO..

I'll correct this.

aircon of central building to cool mode

Today I switched aircon of central building to cooling mode at 22degC.

Still need to be done for END.

Comment to 30mm ; 70 mm 6/6 (Click here to view original report: 3504)

z = 47 mm ; Pt = 4.82 W ; Tue, Apr 2, 2024 6-27-00 PM.txt

Comment to 30mm ; 70 mm 6/6 (Click here to view original report: 3504)

z = 67 mm, Pt = 4.81W : Tue, Apr 2, 2024 2-29-08 PM.txt

30mm ; 70 mm 6/6

this sample is t70#1.

Moved zIU to 40.01 mm

Pt = 25.5mW ; Pin = 30.0mW

There is definitely an issue with the holder : the sample is fixed by 2 set screws which can induce a slight tilt of the sample with respect to the input beam.... However there seems to exist a roll angle that compensate this...

Recentered DC with pink tape at bottom towards IU this time.

z scan with 4.81 W : Tue, Apr 2, 2024 10-17-23 AM.txt

z edges at 37 and 77 mm : center at 57mm

map at z_center : Tue, Apr 2, 2024 10-31-32 AM.txt

Comment to 30mm ; 50mmL : 6/6 (Click here to view original report: 3499)

z = 54mm, Pt = 4.85W  : Mon, Apr 1, 2024 11-58-05 PM.txt

this sample is t50#2

30mm ; 50mmL : 6/6

DC was quite misaligned after changing sample..

after realignment

Pt = 26.1mW ; Pin = 30.0mW

rotated HWP to 28deg : Pt = 4.82W

long z scan : Mon, Apr 1, 2024 9-05-41 AM.txt

z edges at 29.5 and 58.5 mm : z_center = 44 mm

Pt = 4.84W

map at z_center : Mon, Apr 1, 2024 10-26-52 AM.txt

after visit break Pt~4.9W

z = 34 mm : Mon, Apr 1, 2024 4-44-36 PM.txt

Comment to 30mm diameter sapphire absorption (Click here to view original report: 3497)

pt _ 4.65W

map at z_53 mm , Pt _ 4.65W; Sat, Mar 30, 2024 11-35-05 AM.txt

map at 33mm ' Sat, Mar 30, 2024 8-01-36 PM.txt

30mm diameter sapphire absorption

laser : 7 A and HWP = 0deg : ~30mW

surface calib

z_iu = 69.18mm

z = 33 mm, (x,y) = (327.093,119.965)

checked calibration factor from 33 to 36mm, the max is at z=35mm ~13.9/W

z scan : Fri, Mar 29, 2024 11-29-17 AM.txt with Pt = 20.8mW (Pt = 21.4mW corresponds to Pin = 31.4mW)

bulk calibration

Pin = 31.1mW, Pt = 17.1mW to compute transmission

during measurement Pt = 17.5mW

moved z_iu by -0.32mm, z = 33.8mm gives R = 0.6413cm/W

z scan : Fri, Mar 29, 2024 2-27-42 PM.txt

T50#1 (30mm diameter, 50mm length, #4/6)

ziu = 48.61mm

dc was heavily misaligned in vertical... due to holder?

check if center is (x,y) 327,119 we can do +/-10mm in all direction without problem

also dc does not change during this so holder seems fine

Pt = 26.6mW, Pin = 31.2mW

can change z between 20 to 90 mm

HWP = 28deg : Pt = 4.83W

long z scan at x,y center : Fri, Mar 29, 2024 5-33-48 PM.txt

z edges are at 26 and 60 mm :Z_center = 43mm

10 mm radius map at z_center with 5mV gain and Pt = 4.81W : Fri, Mar 29, 2024 6-53-59 PM.txt

I placed a pink tape on top close to IU side

ethernet is back

Even though I already tried few days ago, this time unplugging/replugging the ethernet switch cables seems to have solve the ethernet connection issues of PCI and FC pcs.

Comment to Labview Modification (Click here to view original report: 3492)

The data is being saved in the format below. Also, a header indicating the name of column has been added using "set dynamic attribute", and by enabling the header function in saving measurement to file. 

Data	Column Number
LC1 voltage	0
LC2 voltage	1
LC1 temperature	2
LC2 temperature	3
Mean Transmitted Power	4
STD Tansmitted power	5
Mean Main laser power	6
STD Main laser power	7
Mean Azimuth	8
STD Azimuth	9
Mean Ellipticity	10
STD Ellipticity	11

Labview Modification

In labview the averging filter was modified to include the standard deviation of data and also to save them simultaneously in file. 

Comment to He Recharge (Click here to view original report: 3485)

I checked the He pressure today and did not notice any change. I will add a mark for future reference.