Lab alignment procedure - Revision history

192.153.157.220 at 19:13, 20 October 2013

2013-10-20T19:13:54Z

← Older revision		Revision as of 19:13, 20 October 2013
Line 44:		Line 44:
	7b. The device has a long arm, and doesn't have the adjustment of fine rotation. The question is how do I know if the collimated lens is parallel to the lenslet array. The method I used is to perfect vertical reference like a ruler, and a piece of very thin paper like lens paper. Then push the ruler against the device and use the paper to feel the friction on the top and bottom part of the touched places. If you feel strong friction on both part, then the lens is placed vertically and parallel to the lenslet array.		7b. The device has a long arm, and doesn't have the adjustment of fine rotation. The question is how do I know if the collimated lens is parallel to the lenslet array. The method I used is to perfect vertical reference like a ruler, and a piece of very thin paper like lens paper. Then push the ruler against the device and use the paper to feel the friction on the top and bottom part of the touched places. If you feel strong friction on both part, then the lens is placed vertically and parallel to the lenslet array.

	[[File: alignment_of_collimated_lens1_2013Oct20.~~png~~]]		[[File: alignment_of_collimated_lens1_2013Oct20.jpg]]
	[[File: alignment_of_collimated_lens2_2013Oct20.~~png~~]]
			[[File: alignment_of_collimated_lens2_2013Oct20.jpg]]

192.153.157.220 at 19:13, 20 October 2013

2013-10-20T19:13:10Z

← Older revision		Revision as of 19:13, 20 October 2013
Line 42:		Line 42:

	7a. The device (optosigma, # 111-1310) that holds the collimated lens is not very secure. It is good enough for lab test, but probably not enough for on sky. So use glue to attach the lens to the optosigma device. <br />		7a. The device (optosigma, # 111-1310) that holds the collimated lens is not very secure. It is good enough for lab test, but probably not enough for on sky. So use glue to attach the lens to the optosigma device. <br />
	7b. The device has a long arm, and doesn't have the adjustment of fine rotation~~, so it~~ is ~~hard to put it~~ parallel to the lenslet array. ~~What~~ I ~~did~~ is to ~~visually check if~~ the lens is		7b. The device has a long arm, and doesn't have the adjustment of fine rotation. The question is how do I know if the collimated lens is parallel to the lenslet array. The method I used is to perfect vertical reference like a ruler, and a piece of very thin paper like lens paper. Then push the ruler against the device and use the paper to feel the friction on the top and bottom part of the touched places. If you feel strong friction on both part, then the lens is placed vertically and parallel to the lenslet array.

	[[File:~~pupil_nolens_2013Jun07~~.png]]		[[File: alignment_of_collimated_lens1_2013Oct20.png]]
	[[File:~~focus_onelens_2013Jun07.png]]~~		[[File: alignment_of_collimated_lens2_2013Oct20.png]]
	~~[[File:pupil_twolens_2013Jun07.png]]~~
	~~[[File: alignment_of_collimated_lens_2013Oct20~~.png]]

192.153.157.220 at 19:06, 20 October 2013

2013-10-20T19:06:10Z

← Older revision		Revision as of 19:06, 20 October 2013
Line 16:		Line 16:
	2e. loose the four screws that tight the metal baseplate to the linear xyz stage (newport ultra 562). Rotate the whole metal piece so that the reflected beam matches the incoming beam <br />		2e. loose the four screws that tight the metal baseplate to the linear xyz stage (newport ultra 562). Rotate the whole metal piece so that the reflected beam matches the incoming beam <br />

	'''3. align ~~the center of~~ the beam ~~to the center of the threaded hole of~~ the ~~front metal panel (rough)~~'''		'''3. align the beam with the camera'''

	3a~~. put a second iris close to the camera (theoretically you can first iris, but it is too far away to reach), and beam size small ~1mm. And fully~~		3a. attach the camera to the front metal panel<br />
	~~open the first iris.<br />~~		3b. install the first reimaging lens, you should be able to see a spot on the detector. Then loose
	~~3b. put the cylindrical target into the hole of the front metal panel. Note, the target doesn't tightly fit into the hole, it can be shaken, that's why~~
	~~this step is rough.<br />~~
	~~3c. move the second iris to put the laser beam at the center of the target.<br />~~

	~~'''4. align the beam with the camera'''~~

	4a. attach the camera to the front metal panel<br />
	4b. install the first reimaging lens, you should be able to see a spot on the detector. Then loose
	the screws on the camera, try to move the camera to put the spot at the center		the screws on the camera, try to move the camera to put the spot at the center
	of the final readout area. the readout size should start with full frame so that you can see where the spot is on the detector. Note: we are in crop mode, so if you see		of the final readout area. the readout size should start with full frame so that you can see where the spot is on the detector. Note: we are in crop mode, so if you see
	light in a subarray readout, this doesn't mean the light is really in the subarray area. That's why you want to start out with full frame. <br />		light in a subarray readout, this doesn't mean the light is really in the subarray area. That's why you want to start out with full frame. <br />
	4c. Then take out the lens, you will be see a pupil on the detector. try to move the linear xyz stage of the camera to move the center of the pupil to match		3c. Then take out the lens, you will be see a pupil on the detector. try to move the linear xyz stage of the camera to move the center of the pupil to match
	where the spot was. <br />		where the spot was. <br />
	4d. put on the lens again to check if the spot has moved. If it has moved a little, iterate the above steps to get the spot match the center of the pupil.		3d. put on the lens again to check if the spot has moved. If it has moved a little, iterate the above steps to get the spot match the center of the pupil.
	Here is my understanding of how this step works.		Here is my understanding of how this step works.
	[[File: WFS_lens_misalign_handdrawing.JPG]]		[[File: WFS_lens_misalign_handdrawing.JPG]]
Line 39:		Line 31:
	'''5. align the reimaging lens pair with the camera.'''		'''5. align the reimaging lens pair with the camera.'''

	5a. Then put on the second lens, you will see the pupil again on the detector. The center of the pupil should ~~automatically~~		5a. Then put on the second lens, you will see the pupil again on the detector. The center of the pupil should
	~~match~~ the spot.<br />		be close to the spot (< 5 pixels). If not, there must be some misalignment in the previous steps.<br />

			'''6. align the lenslet array'''

			6a. install the lenslet array, and you should be able to see many spots from the lenslets.<br />
			6b. un-tighten the screws holds the rotation stage to move the rotation stage so that the spots-of-interest are not on the edge of the detector readout array. Usually I will keep at least 3 pixels away from the edge.<br />

			'''7. align the collimated lens'''

			7a. The device (optosigma, # 111-1310) that holds the collimated lens is not very secure. It is good enough for lab test, but probably not enough for on sky. So use glue to attach the lens to the optosigma device. <br />
			7b. The device has a long arm, and doesn't have the adjustment of fine rotation, so it is hard to put it parallel to the lenslet array. What I did is to visually check if the lens is

	[[File:pupil_nolens_2013Jun07.png]]		[[File:pupil_nolens_2013Jun07.png]]
	[[File:focus_onelens_2013Jun07.png]]		[[File:focus_onelens_2013Jun07.png]]
	[[File:pupil_twolens_2013Jun07.png]]		[[File:pupil_twolens_2013Jun07.png]]
			[[File: alignment_of_collimated_lens_2013Oct20.png]]

192.153.157.220 at 18:42, 20 October 2013

2013-10-20T18:42:31Z

← Older revision		Revision as of 18:42, 20 October 2013
Line 1:		Line 1:
	'''1. make sure the input collimated beam is parallel to the table:'''		'''1. make sure the input collimated beam is parallel to the table:'''

	It is relatively easy to mount the camera parallel to the table, so I think it is useful to align the beam parallel to the table too. I also find it is useful to		It is relatively easy to mount the camera parallel to the optical table, so I think it is useful to align the beam parallel to the table too. I also find it is useful to mount the input beam source on a linear stage so that when you align the beam parallel to the table, you can
			easily move the beam around to shoot it into the camera.

	~~1a. put an iris in front of the beam to shrink the laser beam size to ~1mm<br />~~		Depending on the detailed setup, the alignment procedure could be different. Usually it is useful to have a mirror or the source
	~~1b. iteratively place~~ the ~~same target at two places along the beam~~, the ~~two places have to~~ be ~~far apart for high precision~~		that can be steered in tiptilt. Then a common alignment procedure will be to use the tiptilt control to align the same target close to and far away from the beam source. The procedure takes several iteration steps.
	~~and the connection of the two places has to be parallel~~ to the ~~table<br />~~
	1c. ~~adjust~~ the tiptilt ~~of the mirror~~ to ~~make sure the beam hit~~ the same ~~position of the~~ target at the ~~two places~~. The ~~last~~
	~~mirror is for fine adjustment for target at farther position, and the second to last mirror is for coarse adjustment for the target~~
	~~at closer position~~.~~<br />~~

	'''2. make sure the home-made front metal panel is perpendicular to the beam.'''		'''2. make sure the home-made front metal panel is perpendicular to the beam.'''

	2a. assemble the metal pieces, no lens or camera.<br />		2a. assemble the metal pieces, no lens or camera.<br />
	2b. ~~open~~ the ~~iris to be about 5 mm~~<br />		2b. keep the beam size as small as possible (<~ 1mm) <br />
	2c. ~~use~~ the ~~edge of a rectangular card to block half of~~ the ~~beam~~, and ~~let~~ the ~~other half pass through<br />~~		2c. put in the hole-made cylindrical target into the S mount on front metal panel, and move the beam source to be aligned to
	2d. ~~put a~~ flat mirror ~~tightly against~~ the front metal panel ~~(I used one hand to hold and push the mirror) to reflect the passed-through~~		the target. This step can be rough.
	~~half beam~~<br />		2d. install the lens tube with flat mirror (edmund, #45598, #63951) to the S mount on the front metal panel <br />
	2e. loose the four screws that tight the metal baseplate to the linear xyz stage. Rotate the whole metal piece so that the reflected ~~half~~ beam		2e. loose the four screws that tight the metal baseplate to the linear xyz stage (newport ultra 562). Rotate the whole metal piece so that the reflected beam matches the incoming beam <br />
	matches the ~~blocked half beam horizontally (meaning they become a circle, but it is not true if they are not vertically aligned)<br />~~
	~~2f. If the reflected beam and blocked~~ beam ~~don't match vertically, we can put some shims between the triangles panels and the front metal panel.~~
	~~But I didn't find it necessary this time.~~<br />

	'''3. align the center of the beam to the center of the threaded hole of the front metal panel (rough)'''		'''3. align the center of the beam to the center of the threaded hole of the front metal panel (rough)'''

192.153.157.220 at 17:52, 20 October 2013

2013-10-20T17:52:05Z

← Older revision		Revision as of 17:52, 20 October 2013
Line 1:		Line 1:
	'''1. make sure the input collimated beam is parallel to table:'''		'''1. make sure the input collimated beam is parallel to the table:'''

			It is relatively easy to mount the camera parallel to the table, so I think it is useful to align the beam parallel to the table too. I also find it is useful to

	1a. put an iris in front of the beam to shrink the laser beam size to ~1mm<br />		1a. put an iris in front of the beam to shrink the laser beam size to ~1mm<br />

67.194.73.115 at 21:23, 6 September 2013

2013-09-06T21:23:41Z

← Older revision		Revision as of 21:23, 6 September 2013
Line 31:		Line 31:

	4a. attach the camera to the front metal panel<br />		4a. attach the camera to the front metal panel<br />
	4b. ~~switch~~ the ~~light source from laser~~ to ~~white light, and turn~~ on the camera, ~~set exposure~~ to ~~be 0.01s, and keep~~ the ~~second iris small.<br />~~		4b. install the first reimaging lens, you should be able to see a spot on the detector. Then loose
	4c. the readout size should start with full frame so that you can see where the spot is on the detector. Note: we are in crop mode, so if you see		the screws on the camera, try to move the camera to put the spot at the center
	light in a subarray readout, this doesn't mean the light is really in the subarray area. That's why you want to start out with full frame. Then ~~loose~~		of the final readout area. the readout size should start with full frame so that you can see where the spot is on the detector. Note: we are in crop mode, so if you see
	the ~~screws~~ on the ~~camera, and~~ move the camera to ~~put the light roughly at the right area (the left up corner is (0,0), ideally we want~~ the center of the ~~light~~		light in a subarray readout, this doesn't mean the light is really in the subarray area. That's why you want to start out with full frame. <br />
	to ~~be at (45~~,~~45)). When~~ the ~~light is roughly at~~ the center of the ~~90X90 array, tight the screws~~.~~<br />~~		4c. Then take out the lens, you will be see a pupil on the detector. try to move the linear xyz stage of the camera to move the center of the pupil to match
			where the spot was. <br />
			4d. put on the lens again to check if the spot has moved. If it has moved a little, iterate the above steps to get the spot match the center of the pupil.
			Here is my understanding of how this step works.
			[[File: WFS_lens_misalign_handdrawing.JPG]]

	'''5. align the reimaging lens pair with the camera.'''		'''5. align the reimaging lens pair with the camera.'''

	5a. ~~there are three images needs to be aligned:~~ the ~~pupil image without any~~ lens ~~in the front;~~		5a. Then put on the second lens, you will see the pupil again on the detector. The center of the pupil should automatically
	~~the image with one lense in the front;~~ the pupil ~~image with two lens in~~ the ~~front~~. ~~If they are not overlapped,~~		match the spot.<br />
	~~I think it is because the optical axis of the lens is not aligned with that~~ of the pupil~~, as shown in~~ the ~~attached figure~~.<br />
	~~[[File: WFS_lens_misalign_handdrawing.JPG]]~~

	~~5b. use the actuators on the linear xyz stage to move the images on the detector. The two pupil images~~
	~~move in the opposite way if you turn the actuators in the same direction. This confirms my understand of the misalignment.~~
	~~So it is possible to align these two images. You just need to iterate a couple of times.<br />~~
	~~5c. In this case when the two pupil images are align, the image of the focus seems pretty well aligned automatically. If it is not aligned, I haven't~~
	~~thought of how to fix it.<br />~~
	[[File:pupil_nolens_2013Jun07.png]]		[[File:pupil_nolens_2013Jun07.png]]
	[[File:focus_onelens_2013Jun07.png]]		[[File:focus_onelens_2013Jun07.png]]
	[[File:pupil_twolens_2013Jun07.png]]		[[File:pupil_twolens_2013Jun07.png]]

Monnierast at 20:50, 7 June 2013

2013-06-07T20:50:08Z

← Older revision		Revision as of 20:50, 7 June 2013
Line 49:		Line 49:
	5c. In this case when the two pupil images are align, the image of the focus seems pretty well aligned automatically. If it is not aligned, I haven't		5c. In this case when the two pupil images are align, the image of the focus seems pretty well aligned automatically. If it is not aligned, I haven't
	thought of how to fix it.<br />		thought of how to fix it.<br />
			[[File:pupil_nolens_2013Jun07.png]]
			[[File:focus_onelens_2013Jun07.png]]
			[[File:pupil_twolens_2013Jun07.png]]

Monnierast at 20:49, 7 June 2013

2013-06-07T20:49:11Z

← Older revision		Revision as of 20:49, 7 June 2013
Line 42:		Line 42:
	the image with one lense in the front; the pupil image with two lens in the front. If they are not overlapped,		the image with one lense in the front; the pupil image with two lens in the front. If they are not overlapped,
	I think it is because the optical axis of the lens is not aligned with that of the pupil, as shown in the attached figure.<br />		I think it is because the optical axis of the lens is not aligned with that of the pupil, as shown in the attached figure.<br />
	[[File:WFS_lens_misalign_handdrawing.~~jpg~~]]		[[File: WFS_lens_misalign_handdrawing.JPG]]

	5b. use the actuators on the linear xyz stage to move the images on the detector. The two pupil images		5b. use the actuators on the linear xyz stage to move the images on the detector. The two pupil images

Monnierast at 20:48, 7 June 2013

2013-06-07T20:48:49Z

← Older revision		Revision as of 20:48, 7 June 2013
Line 42:		Line 42:
	the image with one lense in the front; the pupil image with two lens in the front. If they are not overlapped,		the image with one lense in the front; the pupil image with two lens in the front. If they are not overlapped,
	I think it is because the optical axis of the lens is not aligned with that of the pupil, as shown in the attached figure.<br />		I think it is because the optical axis of the lens is not aligned with that of the pupil, as shown in the attached figure.<br />
			[[File:WFS_lens_misalign_handdrawing.jpg]]

	5b. use the actuators on the linear xyz stage to move the images on the detector. The two pupil images		5b. use the actuators on the linear xyz stage to move the images on the detector. The two pupil images

Monnierast at 20:42, 7 June 2013

2013-06-07T20:42:32Z

← Older revision		Revision as of 20:42, 7 June 2013
Line 1:		Line 1:
	'''1. make sure the input collimated beam is parallel to table:'''		'''1. make sure the input collimated beam is parallel to table:'''

	1a. put an iris in front of the beam to shrink the laser beam size to ~1mm<br />		1a. put an iris in front of the beam to shrink the laser beam size to ~1mm<br />
	1b. iteratively place the same target at two places along the beam, the two places have to be far apart for high precision		1b. iteratively place the same target at two places along the beam, the two places have to be far apart for high precision
Line 7:		Line 8:
	at closer position.<br />		at closer position.<br />

	2. make sure the home-made front metal panel is perpendicular to the beam.		'''2. make sure the home-made front metal panel is perpendicular to the beam.'''

	2a. assemble the metal pieces, no lens or camera.<br />		2a. assemble the metal pieces, no lens or camera.<br />
Line 19:		Line 20:
	But I didn't find it necessary this time.<br />		But I didn't find it necessary this time.<br />

	3. align the center of the beam to the center of the threaded hole of the front metal panel (rough)		'''3. align the center of the beam to the center of the threaded hole of the front metal panel (rough)'''

	3a. put a second iris close to the camera (theoretically you can first iris, but it is too far away to reach), and beam size small ~1mm. And fully		3a. put a second iris close to the camera (theoretically you can first iris, but it is too far away to reach), and beam size small ~1mm. And fully
Line 27:		Line 28:
	3c. move the second iris to put the laser beam at the center of the target.<br />		3c. move the second iris to put the laser beam at the center of the target.<br />

	4. align the beam with the camera		'''4. align the beam with the camera'''

	4a. attach the camera to the front metal panel<br />		4a. attach the camera to the front metal panel<br />
Line 36:		Line 37:
	to be at (45,45)). When the light is roughly at the center of the 90X90 array, tight the screws.<br />		to be at (45,45)). When the light is roughly at the center of the 90X90 array, tight the screws.<br />

	5. align the reimaging lens pair with the camera.		'''5. align the reimaging lens pair with the camera.'''

	5a. there are three images needs to be aligned: the pupil image without any lens in the front;		5a. there are three images needs to be aligned: the pupil image without any lens in the front;