• The front side of the AO bench is the one where most of the optics and sensors are placed, including the DM, WFS camera, and IRCAL.
• Unless otherwise specified, left, right, up, and down are from the point of view of someone standing upright (!) with the AO bench upright (!!) facing the front side of the AO bench.
• Before and after an object is from the point of view of incoming astronomical photons. Surface 1 is before surface 2 if the light from the star will hit surface 1 first.
• The electronics racks refer to the 24x30x36 black cabinets, which are normally positioned on either side of the AO bench.
• Pulizzi controller: These refer to the computer or manually controlled power strips (located in the electronics and computer racks) that control the power distribution to various components. When directed to power up or power down a component, you can either push a button on the power strip or use software, whichever is more convenient.
• The z-axis is always parallel to the direction of light propagation. Depending on the situation, x and y can refer to either of the two directions orthogonal to the light propagation. Parallel to the table and perpendicular to the table are more often used here to avoid confusion with other, possibly changing and inconsistent, coordinate systems.
• There are two irises associated with the WFS. The small iris inside the WFS (between the collimating lens and lenslet array) will be refered to as the WFS iris. The iris right before the WFS, will be refered to as the iris stage iris. With luck this will keep confusion down to a minimum.

During regular operations one should not have to do the basic alignment. However, if something is horribly misaligned or parts of the system have been altered or removed and reinstalled this procedure may be necessary.

If all is running ok, the basic alignment outlined below should only take a few minutes to an hour to do. The only way for things to get seriously out of alignment is for the bench to be handled roughly enough to dislodge, bump, or break a piece of equipment. The Lick staff are careful and such misalignment or catastrophic damage is unlikely.

1. Install alignment pinholes. There are 5 alignment pinholes 3 of which need to be installed: in front of the first parabola, deformable mirror (DM), and the second parabola. Make sure to mount the pinholes such that the number label on the pinhole matches the number label on the post holder and that the scribe marks on the pinhole mounts and postholders are aligned. 2 alignment pinholes are permanently mounted: behind the first mirror after cassagrain focus and before the TT Cube.
2. Connect battery powered red laser to alignment fiber (or you can connect the HeNe fiber to the alignment laser).
3. Adjust RLS brightness to maximum if using the HeNe laser. If there is little light coming out of the alignment laser check the following:
   • Fibers are well coupled at the FC connector.
   • Fibers may need to be cleaned.
   • RLS (HeNe) alignment may need adjusting. (Detailed directions to come...)
4. Move fiber stage out of way. This can be done via software or (if the motor is turned off) manually by pushing the stage out of the way and holding it there by inserting a block in the mount to keep it in the out of the way position.
5. Remove 1st Turning Mirror. This is the mirror just before the cassegrain focus. Unscrew the 3 clamps, on back of mount, holding the mirror in the mount. Make sure that each clamp is put back into the same position as when the mirror was in the mount. The 3 clamps are not identical and not interchangable. If they are swapped the mirror will be in a significantly different position and alignment on the sky will be difficult (sky alignment directions to come later....)
6. Remove 1st mirror after Cassegrain focus. Remove the 3 spring loaded screws from the front of the mirror mount and carefully remove the mirror.
7. Align through first pinhole (which is located behind the 1st mirror after cassegrain focus).
   1. Center alignment laser on pinhole by moving the motors on the alignment laser mount. The most sensitive way to do this (for any pinhole alignment) is to make the iris slightly smaller than the laser spot and adjust until there is an even halo of light around the hole.
   2. Reinstall 1st mirror after cassegrain focus.
8. Align through pinhole #1.
   1. Turn on TT 100V supply (make sure it is supplying 100V and not in standby mode). The supply may need programming if it has just been turned on. Make sure it is in standby mode, type 100 on the keypad and press enter. Then take it out of standby mode to supply 100V to the mirror.
   2. Move 1st mirror after cassegrain focus to center alignment laser on pinhole #1.
   3. Make sure that alignment laser is roughly centered on the TT mirror. The penalty for being off center is a somewhat reduced field-of-view, approximately 4 arcsec/mm. If it is not centered something is seriously awry: either the position of the permanently mounted first pinhole has been changed or the position of pinhole #1 has been changed. Easiest to check is beam height. Beam height should be 7.5 inches above the table.
9. Align through pinhole #2.
   1. Open pinhole #1.
   2. Move 1st mirror after cassegrain focus to center alignment laser on pinhole #2. This should be a small movement.
   3. Close pinhole #1 to see how far off center the spot is. If off center by less than 1mm, proceed to next step.
      NOTE: It is typical that when perfectly aligned through pinhole #2, that the spot will be low (by a mm or two) on either or both pinhole #1 and #3. This is OK. Penalty for being off center is a reduced field-of-view (4 arcsec/mm) and some added common path astigmatism. Small common path aberrations can be calibrated out later and are not of much concern. If off by more than a few millimeters, you may need recenter through pinhole #1 and tilt the parabola to center through pinhole #2, by using the screws on the back of its mount. Before tilting the parabola, check to see how far off center the alignment laser is on pinhole #3. If this is also off by more than a few millimeters, then tilting of the 1st parabola needs to be done as well as tilting the DM. WARNING: Only undertake tilting the 1st parabola and DM if absolutely necessary (i.e. things are very far off and you are sure there no other problems). It is very difficult to tilt the DM and small aberrations are preferable to the pain of changing this alignment or the chance of messing up the registration of the actuators with the subapertures.
10. Align through pinhole #3.
    1. Open pinholes #1 and #2.
    2. Evaluate how far off center the spot is on pinhole #3. If off center by less than a couple millimeters and well aligned through pinhole #2, don't do anything else. Move 1st mirror after cass focus if you think you can get a reasonable compromise alignment through pinholes #1, #2, and #3. See note above about typical alignment.
    NOTE: Proper alignment through Pinhole #2 is most important. It is typical for the spot to be slightly off center on pinholes #1 and #3 (usually a millimeter or so high on #1 and a couple millimeters low on #3, if this is the case, don't bother moving either parabola or the DM tilt).
11. Align to 1st Dichroic. Alignment laser should be below center on the 1st Dichroic, but centered on the turning mirror behind it. If necessary (shouldn't be if nothing has changed with respect to 1st parabola and DM tilt), tilt the 2nd parabola to steer beam to the center of the turning mirror behind the 1st Dichroic.
12. Align through TT Cube pinhole.
    1. If only aligning for NGS mode and the mirror is in the 2nd Dichroic mount, move the 1st Dichroic so that the alignment laser is roughly centered on the mirror.
    2. If the dichroic is in the 2nd Dichroic mount, move the 1st Dichroic to center the beam through the TT Cube pinhole. This will, by default, put you well centered on the 2nd Dichroic.
13. Align to center of WFS Steering mirror.
    1. Place the small paper target on the WFS Steering mirror.
    2. Move 2nd Dichroic to center alignment laser on the target.
    3. Remove target.

1. Record micrometer positions for all the optics in the WFS. While this isn't strictly necessary, it can be helpful if things go terribly awry and you need to get back to where you started.
2. Remove all WFS optics. Make sure they all have locating blocks before you remove any of the optics! The lenslet array doesn't have a designated locating block, so you will have to move the WFS iris and use it as a locating block for the lenslet array.
3. Move WFS Steering mirror to center laser on the WFS camera chip.
4. Start real-time control software if it is not already running.
5. Turn off lights, darkness is required for the rest of this procedure.
6. Do the following iterative procedure until spot is centered on WFS camera crosshairs both with and without the 1st Reducing lens in.
   1. Adjust brightness of alignment laser so that WFS camera is not completely saturated.
   2. Insert 1st Reducing lens.
   3. Move 2nd Dichroic to center spot on WFS crosshairs.
   4. Remove 1st Reducing lens.
   5. Move WFS Steering mirror to center spot on WFS crosshairs.
7. Install 1st Reducing lens if it isn't already in place.
8. Install 2nd Reducing lens.
9. Steer 2nd Reducing lens in X and Y to center spot on WFS crosshairs.
10. Install Collimating lens.
11. Steer in X and Y to center spot on WFS crosshairs.
12. Install fiber chuck on the Iris stage.
13. Move Iris stage to center fiber chuck on alignment laser.
14. Insert RLS fiber in the fiber chuck.
15. Collimate Collimating lens.
    1. Remove the filter wheel. This is necessary so there is enough room to put in the shear cube.
    2. Put the small shear cube between the Collimating lens and the lenslet array position.
    3. Move the Iris stage in Z (using the micrometer) until the fringes are parallel to the shear cube fiducial.
    4. Remove the shear cube.
    5. Install the filter wheel.
16. Install Lenslet array.
17. Make sure that real-time code is running with the quadcell centroider and using the scratch parameters. Also make sure that the hartmannModes are all zero.
    Type the following into CentDiag.
    1. centquad
    2. sparms
    Zero all zernike modes in CentDiag HartmannModes GUI.
18. Align lenslet array. Perform the following steps iteratively until all hartmann spots in the CentDiag display are within their inner circles at the highest magnification.
    1. Adjust brightness of RLS so that there are approximately 10000 to 15000 counts per subaperture on the CentDiag display.
    2. Center hartmann spots by moving 2nd Reducing lens X and Y. Use the CentDiag display to measure tip and tilt. Try to get both tip and tilt to be within +-0.05.
    3. Adjust Lenslet array rotation. Repeat the following until rotation is as close to 0.0 degrees as possible (usually to within a tenth of a degree).
       1. Take WFS Data
       2. Use aoIDL to measure WFS rotation. This program will calculate the overall rotation of the hartmann pattern and predict the amount and direction of the goniometer move.
       3. Turn goniometer the suggested amount
       4. Take more WFS Data, etc.
    4. Focus hartmann spots by adjusting CCD focus micrometer. This should be unnecessary since we are no longer changing to a different lenslet array for LGS mode. If it is necessary, do the following:
       1. Record the X and Y micrometer positions of the 2nd Reducing lens.
       2. Record the CCD Focus micrometer position.
       3. Steer 2nd Reducing lens in X and Y until the light for each hartmann spot is centered on a single pixel.
       4. Adjust the CCD Focus micrometer until you get the smallest spots possible. You may have to keep adjusting the X and Y position of the 2nd Reducing to keep the spots centered on a single pixel.
       5. If you get lost or confused, return to your starting point and try again (this is why you wrote down those micrometer positions).
    5. Center hartmann spots by moving 2nd Reducing lens X and Y.
    6. Adjust WFS magnification (should not be necessary unless something drastic has happened - standard position on micrometer is 4.060)
    7. Coarse Focus WFS
       1. Take an WFS camera background, i.e. turn off RLS and push the cflat button in the CentDiag window.
       2. Change to the QuadCell centroider, i.e. type centquad into the CentDiag window.
       3. Make sure that you are using scratch parameters, i.e. type sparms in CentDiag.
       4. Use the CentDiag display to measure the wavefront focus.
       5. Move Iris stage Z micrometer until Focus is close to 0.0, e.g. within +-0.005.
19. Fine WFS Alignment. Do the following iterative procedure until focus, tip, and tilt are all 0.0 (+- 0.01).
    1. Focus WFS: Move Iris stage Z until CentDiag focus is as close to 0.0 as possible (within a couple of hundreths).
    2. Center Spots: Move Iris stage X and Y until CentDiag tip and tilt are 0.0.
20. Take Reference Centroids for all the algorithms
    For lgs7 type the following into CentDiag:
    
    1. refcent
    2. centcm
    3. sparms
    4. refcent
    5. centbin
    6. sparms
    7. refcent
    8. centcorr
    9. sparms
    10. refcent
21. Move WFS iris from being the lenslet locator block back to right in front of the WFS filter wheel.
22. Close WFS iris. The hartmann spots making it through the iris should be close to the center of the WFS crosshairs. Note which spots are illuminated. Pointing and Centering adjustments later should cause the same hartmann spots to be illuminated when properly aligned through the iris stage iris and WFS optics.
23. Open WFS iris.

Micrometer motions: To assist with aligning the WFS optics, the following table describes which micrometer does what and which direction to turn the micrometers for the desired effect. Many of these adjustments are unnecessary for typical alignment and listed for reference only.

Effect	Optic	Micrometer or Axis	Direction
Steer spots left/right	2nd Reducing Lens	Perpendicular to AO bench	Left = CCW Right = CW
Steer spots up/down	2nd Reducing Lens	Parallel to AO bench	Down = CCW Up = CW
Move intensity pattern left/right	Collimating Lens	Perpendicular to AO bench	Right = CCW Left = CW
Move intensity pattern up/down	Collimating Lens	Parallel to AO bench	Up = CCW Down = CW
Rotate intensity pattern	Lenslet Array
Coarse adjustment of focus/magnification of spots	WFS Focus motor	Z
"Blow out" spots	2nd Reducing Lens	Z
"Suck in" spots	2nd Reducing Lens	Z
Coarsely focus spots on CCD	Lenslet Array	Z
Fine focus spots on CCD	Focus stage under Lenslet Array	Z

For reference, the micrometer positions for each WFS optic (NGS lenslet array, which, starting in 2002, is also used for LGS mode) are listed below. If after alignment the Strehl is not good (as measured on IRCAL) and the micrometer measures are very different from the following, there may be a problem. If the measured Strehl is good, then don't worry.

NGS WFS (2001 Oct 24)
Stage & Axis	Micrometer Position
Iris Stage Z	7.120
1st Collimating Lens X	1.110
1st Collimating Lens Y	3.468
1st Collimating Lens Z	5.7001
Lenslet Array Goniometer	7.8502
CCD Focus	4.1862
Wavefront Focus	4.0601
2nd Reducing Lens X	6.200
2nd Reducing Lens y	7.223

Notes:
1. These should not ever change.
2. These are significantly different from the current setup due to these components being disassembled and re-assembled after the October AO run.

Just in case we ever go back to using the LGS lenslet array the following table lists the micrometer positions (on 2001 Oct 24) so one can see the relative differences in the positions.

LGS WFS (on 2001 Oct 24)
Stage & Axis	Micrometer Position
Iris Stage Z	11.230
1st Collimating Lens X	1.110
1st Collimating Lens Y	3.468
1st Collimating Lens Z	0.001
Lenslet Array Goniometer	4.0752
CCD Focus	2.6552
Wavefront Focus	4.0601
2nd Reducing Lens X	6.210
2nd Reducing Lens y	7.378

Notes:
1. These should not ever change.
2. These are significantly different from the current setup due to these components being disassembled and re-assembled after the October AO run.

1. Connect the HeNe RLS or the battery powered laser to the alignment laser fiber.
2. Adjust brightness of HeNe RLS to maximum if using it.
3. If you followed the basic alignment directions, you should already be aligned to the center of the first mirror after the 1st Dichroic (1st IR mirror). If not, go back and check your basic alignment.
4. Move the 1st IR mirror micrometers to center the alignment laser on the 2nd IR mirror.
5. Make sure the dark cover is on IRCAL. It has two screws to ensure it is positioned correctly. On the center of the cover is a very hard to see crosshair.
6. Move the 2nd IR mirror micrometers to center the alignment laser on the dark cover crosshairs.

1. Install shear cube table.
   1. Unscrew IRCAL's vent tube (it gets in the way of the table).
   2. Install table above IRCAL. There is a screw and positioning block above IRCAL to make sure that the table is aligned properly.
   3. Make sure table is screwed on securely.
2. Connect RLS (HeNe or battery powered laser) to Point Source fiber.
3. Adjust HeNe RLS so it is at maximum brightness if using it.
4. Collimate 1st Parabola.
   1. Set large shear cube on the installed table. Make sure the input port is facing the 1st parabola and is flush against the attached block. Have the fiducial screen facing up. The shear plate should intercept the center of the beam and be normal to the beam. If the shear plate is not normal to the beam, then you change the tilt of the fringes, which yields erroneous results.
   2. Adjust Fiber Stage Z micrometer so the fringes are parallel to the fiducial line on the screen.
   3. Rotate shear cube so fiducial screen is facing out (the most easily visible orientation).
   4. Evaluate the astigmatism and other aberrations. Typically, there will be about a half fringe of tilt. This is OK and no further adjustment is needed. For reference: At 532nm, 1 fringe of tilt = 1 mm of z-motion = 1 wave P-V of focus. 1 wave P-V of focus => spot from edge subaperture is 0.08 pixels displaced from the center of the quad-cell crosshairs, cf. approximately 0.5 pixel spot size. 1 waves of astigmatism = 30 arcsec off-axis on the sky = 8 mm off-axis parallel to table. Not-flat fringes indicate there is some surface figure in the mirror. There isn't anything you can do about it. With temperature changes, the mirror will change shape somewhat. It can take a day or two for it settle once on the telescope. Also, the focus can shift some from day-to-day; focus changes of several millimeters are not uncommon.
5. Collimate 2nd Parabola.
   1. Connect RLS to fiber chuck in the iris stage so that light is propagating backwards through the AO system.
   2. Set large shear cube on the installed table so that it is propped up on the attached block. Make sure the input side is facing the 2nd parabola and the fiducial screen is facing up.
   3. Move WFS Focus stage until the fringes are parellel to the fiducial line.
   4. Rotate shear cube for fiducial screen is facing out (the most easily visible orientation).
   5. Evaluate the astigmatism and other aberrations. Typically there will be a quarter fringe of tilt. This is OK and can be calibrated out later. Alignment tolerances are about twice as loose for the 2nd parabola as for the first (linear dimensions only, due to the f/28 rather than f/17 focal ratio of the 2nd parabola). If there more than a fringe of astigmatism you might want to consider adjusting the tilt of the second parabola. Only embark on this procedure if you are sure there is nothing else wrong to cause the excessive astigmatism.
      1. Adjust WFS focus to flatten the fringes on top.
      2. Adjust tilt on the 2nd parabola (parallel to table only) so that the slope of the front fringes is cut in half.
      3. Repeat until the two orientation both give flat fringes.

This process can take anywhere from 15 minutes to an hour to perform.

1. Put Fiber stage at Red Light Source position.
2. Make sure IRCAL software is running.
3. Make sure tip/tilt mirror is in the E-Null position.
4. Put all IRCAL filter wheels in the Open position.
5. Repeat the following until the spot is centered on IRCAL:
   1. Take image on IRCAL. 100ms to 1000ms exposure time depending on brightness of the HeNe laser.
   2. Use fhwm tool on IRCAL Image Browser to determine spot centroid position.
   3. Manually move 1st IRCAL turning mirror in x and y to center spot on IRCAL. A 1/4 chip move is approximately 5 tics on the micrometers.
6. Move the Fiber stage to LGS Simulator position.
7. Connect the red diode laser to 200micron source.
8. Repeat the following until the central obscuration on IRCAL is centered.
   1. Take image on IRCAL. 100ms to 1000ms exposure times are typical, depending on RLS brightness.
   2. Manually move 2nd IRCAL turning mirror in x and y to center obscuration on IRCAL. A typical move is 3 or 5 tics on the micrometer. The pattern is often difficult to interpret, so use your best judgement on when the central obscuration is truly centered.
9. Repeat this entire procedure until pointing and central obscuration centering is good. Be forewarned that this is an iterative and somewhat tedious process.

1. Connect RLS to the Point Source fiber if it isn't already connected.
2. Adjust brightness of RLS until there are approximately 10000 to 15000 counts per subaperture on the CentDiag display.
3. Make sure Tip/Tilt Mirror 100V supply is on.
4. Make sure you are in the QuadCell centroider.
   Type the following into CentDiag:
   1. centquad
5. Open P & C window in LickAO software.
6. Make sure P & C motors are in POS mode in the motor control GUI.
7. Repeat the following until Pointing and Centering look good. Please note that changing pointing can change the centering, and that centering adjustments may change the pointing a little bit.
   1. Adjust Pointing to best center the spots on the WFS camera crosshairs. Use CentDiag tip and tilt numbers to evaluate how well centered the spots are. NGS WFS plate scale is 2 arcseconds per pixel. LGS WFS plate scale is 4 arcseconds per pixel. Note: We no longer use the LGS lenslet array, we now use the NGS lenslet array for both NGS and LGS observing.
   2. Adjust Centering to best evenly illuminate all subapertures. Note that there is often a gradient in the illumination pattern, so do your best to account for it when deciding how to adjust the centering. A typical large centering adjustment is 50 Renishaw encoder counts. A small adjustment is 3 counts.
8. When finished, Assert Zero for the 2nd Dichroic and WFSM motors in the motor control GUI. Also, reset the cummulative offsets for the P & C mirrors.

1. Move Fiber stage to White Light Source position.
2. Turn on White Light Source. If necessary, adjust brightness so that there are at least 5000 counts per subaperture.
3. Turn on DM 100V power supply if it isn't already on.
4. Close TT Loop.
5. Adjust Centering if necessary. This should not be necessary if you just adjusted the Pointing and Centering, as described above.
6. Close AO Loop.
7. Make a new mirror flat. This is not a necessary step, but makes miscellaneous adjustments and calibrations to the system easier.
   For lgs7 type the following into CentDiag:
   1. msharp
   2. sharpen to apply the shape to the mirror when the loop is open.
8. Put in IRCAL's Br-Gamma filter.
9. Set auto fwhm in IRCAL Image Browser.
10. Take an exposure (100ms x 10 coadds is a typical exposure time) and make sure image isn't saturated or likely to saturate as focus changes.
11. Run the imagesharpen script in IRCAL for just the focus, which automatically does the following steps (in case the script fails and you must manually focus):
    1. Put IRCamFocus number in the focval box in Image Browser.
    2. Press "focfit init" button if first focus measurement, otherwise press "focfit" button.
    3. Adjust IRCamFocus (steps of 200 renishaw counts are typical).
    4. Repeat entire procedure and set IRCamFocus to best focus value determined by focfit program.

Procedure is the same as for IRCAL Focus, except do for each mode in the CentDiag Hartmann Slider GUI. Typical step size is 5 for all modes. Mode 1 is not adjusted and should always be left at 0.