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P3K Stimulus Design Update
PALM-3000
Rick Burruss
P3K Team Meeting #7
February 27, 2008
PALM-3000
Current Stimulus
PALM-3000
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Requirements Overview
Highlights from the Stimulus Requirement Document (StRD) version 1.1 (12/11/07)
– There shall be a source that produces light over the entire spectrum used by the instrument
(0.4-2.2um) that can be located at the equivalent of the telescope image plane (Science
source)
– There shall be a source that produces light at 589nm +/-10nm that can be located at
the equivalent of 90km focus (LGS source) P3K-IRD-0465
– There shall be a source that is bright enough to be visible to the eye at full beam size (4.5”
diameter) that can be located at the equivalent of the telescope image plane (Alignment
Mode)
– At least one source shall have a pupil stop at the location of the telescope pupil image
– The Science source shall be adjustable in focus by +/-25mm
– The Science source shall have a translation range of +/- 10mm in the x and y
directions
– The LGS source should be adjustable in focus from the equivalent of 80 to 120km
– Stimulus shall have a seeing-size effective spot size of 0.5-1” for NGS
– All sources shall have variable intensity
– The stimulus package shall be configured such that the LGS and Science sources can
be used at the same time
– The stimulus package shall fit within current box
Optical Design Top View
PALM-3000
White Light
Aerotech Stages
X, Y, Z
594 Laser
Aerotech Z Stage
80:20 Beamsplitter
OAP1
Beam Entrance
Hole (old fold mirror)
Pupil Mask Flipper
FM2
FM1
OAP2
Conjugate
Telescope
Focus
PALM-3000
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The New P3K Stimulus
All reflective design; pupil shared by all 3
sources
We will re-use 3 pieces of the current stimulus
1. The white light source and fiber in the rack
2. The HeNe alignment laser
3. The fold mirror (and Newport motor) on the AO bench will
be retained in its current location and height
•
•
•
All other pieces in the current stimulus package
will be removed
We will build the new stimulus package on a
duplicate breadboard (24” x 24”) at JPL
Work will be done by April 9, May 9 at latest
Rack Design Front View
PALM-3000
New additions are in RED
QuickTime™ and a
TIFF (LZW) decompressor
are needed to see this picture.
Newport Versastar 0.5” filter wheel
c = 1550 nm
c = 460 nm
PALM-3000
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Light Source Issues
White Light Source magnitudes
– R-band (WFS) = 2.3
– K-band (Pharo) = -0.3
– The new white light will be 30% fainter than the old white light due to beamsplitter and
reflective surface loss
•
The 632 nm alignment laser will project in multi mode when using the white light
fiber (2 lobes in V-band), although most of the light (>85%) remains in the core
of the fiber output.
•
The 632 nm alignment laser may be used as a single mode alignment source
through the 594 nm laser fiber with the 594 fiber output Aerotech stage set to 0
km.
•
The 2 laser source intensities may be reduced by using a combination of neutral
density filters mounted in a manually selectable filter wheel placed at the output
of both lasers.
594 and 632 Magnitudes
PALM-3000
For the 594 and 632 nm laser magnitudes of the new design, we calculated the overfill loss
at the pupil in the stimulus, assumed 20% loss at the fiber couple, 2% loss at each optical surface,
and an 80:20 beam splitter at the 594 nm input
Source
Fiber Used (mode)
ND Used
Mag @ WFS
594
594 (single)
None
-8.5
594
594 (single)
4.0
1.5
594
594 (single)
4.0 + 2.0
6.5
594
594 (single)
4.0 + 3.0
9.0
594
594 (single)
4.0 + 4.0
11.5
632 *
594 (single)
None
-9.6
632 *
594 (single)
4.0 + 4.0
10.4
632
White Light (multi)
None
-9.3
632
White Light (multi)
4.0 + 4.0
10.7
* The 594 nm laser stage must be moved to 0 km for 632 source alignment
PALM-3000
Science Focal Spot Diagrams
• 450 to 2200 nm Spot Diagram at center, +/- 1 mm, and +/- 10 mm
PALM-3000
Alignment Tolerances
• Stimulus source total wavefront error requirement
= 300 nm / (2)1/2 = 212 nm
• OAP vendor (B-Con) guarantees /4 with best effort to /8. /4 OAP
fabrication surface error results in 112 nm wavefront error for 2 OAPs
• Final wavefront error =
[(alignment errors)2 + (fabrication errors)2]1/2 = 212 nm
• Wavefront error from alignment will not exceed 180 nm to satisfy total
wavefront error requirement
PALM-3000
Cable / Controller Additions
• The existing Aerotech EPAQ controller will be
modified to run 7 stages (it currently controls 3
stages)
• The 4 new Aerotech stages in the stimulus will
connect to the existing Aerotech controller via 4
10 meter cables, which will be bundled together
PALM-3000
Stimulus Cover
Handles
Pupil Access
Output opening
Side Pupil Access
Final Cost List
PALM-3000
Name
Quantity
Vendor
Cost
2 OAP mirrors
2
B-Con
(total)
6750
X,Y stages (ATS-50-25)
2
Aerotech
(total)
8295
460 nm cutoff fibers (2 m and 5 m)
2
Thorlabs
(total)
166
460 nm cutoff fiber (10 m)
2
Thorlabs
(total)
336
ND filter wheel hub
1
Newport
ND holders (12.7mm diam x 10 mm thick)
5
Newport
2.0 ND filter (12.7 mm diam x 2 mm thick)
1
Thorlabs
20
3.0 ND filter (12.7 mm diam x 2 mm thick)
1
Thorlabs
20
4.0 ND filter (12.7 mm diam x 2 mm thick)
5
Thorlabs
(total)
100
OAP Gimbal Mounts (Bartos - FQPM)
2
In House
(total)
500
80:20 beamsplitter
1
CVI
310
Fiber Coupling Hardware
1
Thorlabs
516
Pupil flipper mount
1
NewFocus
248
Mechanical Fabrication of Pupil Mask
1
JPL (Bartos)
200?
Mechanical Fabrication of Cover
1
Caltech (Bui)
2000?
109
(total)
Total
Items in hand are green, items on order are blue
145
$ 19715
PALM-3000
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Pencil Beam
A pencil beam laser source, a fold mirror, and a magnetic kinematic mount
will be permanently added outside of the stimulus cover for AO lab testing.
These additions will not vignette any part of the stimulus beam nor will they
block the off-axis relay mounts. The second fold mirror will be permanently
fixed to the magnetic mount’s twin for quick and easy assembly.
Permanent Mount
Temporary Fold
Permanent Laser
Permanent Fold
PALM-3000
Phase Screens
• During the design review, CD jewel case covers
were suggested as a simple cost-effective
method to generate various spot size disks in
the output beam of the stimulus.
• Once the stimulus is working, we can try this
• The 6” diameter door on the top of the cover
should allow easy access and jewel case
placement (pieces of plexi-glass?)