KPF Reformatter
Table of Contents:
Reformatter Final Report (and Details)
Description | File(s) | Notes |
|---|---|---|
FInal Winlight Report |  | Second (corrected) version. |
Steve's Questions to Winlight | | Posted here as the email chain helps explain the coordinate system used by Winlight |
Reformatter Reference Surfaces | A slide deck made by Steve to help clarify the reference surfaces used for the Winlight positional measruments. |
Reformatter Procedures
Description | File(s) |
|---|---|
Reformatter Packing Procedure | |
Fiber Block Integration Procedure | |
Reformatter Repair Visit by Winlight
Description | File(s) |
|---|---|
Description of Repair | |
Photos of Repair | KPF_reformatter_pictures_1_of_3.zip |
Latest STEP File
Date | Source | File | Notes |
|---|---|---|---|
April 6, 2021 | WL | Version with corrected height and correct angled end. Note WL did not up-rev the file name. | |
March 22, 2021 | WL | Version with corrected cover height but square end. | |
June 25, 2020 | WL | STEP file from Clement after they corrected the orientation of the fiber block. |
End of Manufacturing Before Coating Review
Description | File | Notes |
|---|---|---|
Delivery Note | ||
Meeting Notes | from Clement, Kodi, Steve | |
Slicer Mirror Inspection Reports | Slicer Mirror 1 Slicer Mirror 2 Slicer Mirror 3 Slicer Mirror 4 Slicer Mirror 5 Slicer Mirror 6 Slicer Mirror 7 | |
Pupil Mirror Inspection Reports | Pupil Mirror 1 Pupil Mirror 2 Pupil Mirror 3 Pupil Mirror 4 Pupil Mirror 5 | |
Afocal Mirror Inspection Reports | Afocal 1 Afocal 2 | |
Mirror Stack Inspection Reports | Slicer Stack S/N 1 Slicer Stack S/N 2 Pupil Stack S/N 1 Pupil Stack S/N 2 |
Post-CDR
Description | Date | Source | File | Notes |
|---|---|---|---|---|
Updated Optical Design Report | Jan 7, 2020 | WL | Rev 'E' | |
Zemax non-sequential model | Jan 7, 2020 | WL | ||
Updated fiber alignment tolerances | Dec 18, 2019 | Steve | ||
Fiber block tolerancing stack-up | Dec 18, 2019 | Steve | Fiber block tolerancing stack-up - side-to-side 15um update.pptx | |
Fiber block interface clarification and tolerances | Dec 11, 2019 | KPF/WL | Winlight response to KPF questions | |
Reformatter STEP file (with cover) | Dec 6, 2019 | WL |
CDR Acceptance
KPF Comments and questions for post-CDR phase
Winlight answers:
CDR Close-Out
End-of-CDR KPF Analyses
Topic | Lead | File | Notes |
|---|---|---|---|
Change of reformatter f/num with wavelength | Steve | OK. | |
Reformatter clocking tolerance | Steve | OK. | |
Chief ray vs. footprint aiming | Ed | OK. KPF team decided footprint aiming was more important, | |
Impact of WL align tolerances on image and pupil in spectrometer | Steve | Reformatter Internal Alignment Tolerances - Image.pptx Reformatter Internal Alignment Tolerances - Pupil.pptx FITS files from 'image' analysis above: | OK. |
KPF Post-CDR Summary and Questions:
KPF CDR Closeout comments/analysis:
Our summary of CDR, and further questions, sent to Winlight:
Latest Reformatter Data Pack:
CDR_data_pack_062119.zip - dated 6/21/19
Data Pack Documents:
Description | File | Comments |
|---|---|---|
Winlight slides from CDR | ||
WL Response to KPF post-CDR slides | ||
Latest Post-CDR Optical Report | Rev 'B' was in original data pack. | |
Post-CDR Mechanical Report |
June 21, 2019 email attachments (to accompany data pack):
Description | File |
|---|---|
Reformatter assembly drawing | |
Base and cover assembly | |
Cover drawing |
Email questions (dates given to help inbox-searching)
KPF Sign-off: OK/NO | KPF Question July 1, 2019 | WL Answer July 4, 2019 | KPF Response July 5, 2019 | KPF Clarification July 8, 2019 | WL Response July 11, 2019 | |
|---|---|---|---|---|---|---|
| 1 | OK for CDR | Would you please send us the solid model of the current entire reformatter? Please also include the solid model of the cover. | I will send to you the solid model (STEP file) of the reformatter once it is updated with your straylight mask request (see question 4 – 6). | Thank you. | ||
| 2 | OK | In WO4681-001-DJD001-B, page 16, section 5.8 analyzes the “the global tilt (including x and y axis) of the output image”. To be clear, our specification asks for a limit on “the common angular error among all five output chief rays”, not the output image. Do you mean to say chief rays? a. Also, we wish to clarify the requirement. Currently it says “the common angular error among all five output chief rays shall be less than 0.25 degrees around the … z axes.” But it is better to say, the rotation of the output image around the z-axis shall be less than 0.25 degrees. To be clear, KPF plans to correct common errors below these limits with shims at the mounting interface, and the intention of this Req.8 is to specify a limit on how many shims we will need. In this section, will you respond to this requirement, now that we say it more clearly? | You are right my sentence is not enough clear. I would like to say “the output image chief rays global tilt”. | Thank you, that is clear now. Please also answer our other comment about this requirement: 2a. Also, we wish to clarify the requirement. Currently it says “the common angular error among all five output chief rays shall be less than 0.25 degrees around the … z axes.” But it is better to say, the rotation of the output image around the z-axis shall be less than 0.25 degrees. To be clear, KPF plans to correct common errors below these limits with shims at the mounting interface, and the intention of this Req.8 is to specify a limit on how many shims we will need. In this section, will you respond to this requirement, now that we say it more clearly? | Regarding your comment in red for #2a, I added in the WO4681-001-DJD001 document a comment about the global tilt around Z axis of the output image. To summarize my comment, the main contributors to this error is the tilt around Z of the fiber in the block. | |
| 3 | OK for CDR Was addressed in Rev D of optical design report. Seems to have a unit typo within calculation? - yes, confirmed by WL | Can you revise the plot on page 22, and concentrate on fitting mutiple data points between 0 to 20 microrad of relative direction error (the y axis)? This will give a much more accurate fit, so that you may derive the correct value for triplet decenter from the 6 microrad specification. We are still interested in the plot out to 5 microns of triplet decenter (the x axis), so please calculate data points there also. | I revise the plot on page 22 to have more data point in the 0 to 5 µm range of triplet decenter. It does not change significantly the results i.e. the decenter stability needed to keep the 6 µrad stability becomes 0.122 µm instead of 0.127 µm. | Please show us the plot and the calculation. We are confused by the calculation, and it would be helpful for us to read it. For example, in the last version of WO4681-001-DJD001-B that we have seen, the data is fit with a line, 𝛿𝜃 = 47165𝛿𝑦 ∓ 6.0345. We would expect 𝛿𝜃 =0 at y=0, but that is not what the linear fit shows. In fact the error is 6.0345 microrad, which is roughly the value that we are seeking! So it seems that the fit needs to be better. Perhaps the data is better fit with a polynomial? Please review the calculation and consider how to fit the data better. | ||
| 4 | OK for CDR Still some work to do on design of pinhole/mask (KPF and WL) | In the documents that we sent last October, we requested mechanical accommodation to mount a 10 um pinhole and 50 um obscuration mask pinhole at the output image location, to aid our spectrometer alignments. See the attached slides. These masks can be removed and replaced as needed. This accommodation is not described in your CDR documents. Will you include this in the reformatter design? | This is not included in the reformatter design. If you want to add this accommodation could you provide the 10 µm pinhole and 50 µm obscuration mask pinhole design and a description of the interface needed. | Yes, we do want to add this accommodation. We will discuss the specific masks we wish to use, and provide you with more information soon. (For the pinhole, we originally showed this product in our slides: https://www.thorlabs.com/thorproduct.cfm?partnumber=LMR05AP. However, we now understand that this part is 25 mm diam, so it is too large - it would block the beam between the two relay mirrors. We will consider an alternate.) | We have considered the specific masks that we want, and after more thought, we believe that we can make custom masks and support them without needing an interface from Winlight. For example, we can design a foil aperture that rests on the Winlight mask at the output image (#5 below). For our alignment, our mask does not even have to be in perfect focus at the output image, rather it could be defocused on the order of a millimeter. The lateral tolerances are also loose. In summary, we do not need Winlight to include accommodation for pinholes. However, we do need the volume around the output image to be accessible, so that we may put in our own apertures. When Winlight shows us their design for the output image mask, then we can consider how the volume is accessible for our needs. And of course, we will need to remove the cover temporarily. This also means that the Winlight mask at the oversized output image (see #5 below) does not need to be removeable. Winlight can permanently install the mask during their integration. | |
| 5 | OK for CDR Still some work to do on design of mask (KPF and WL) | Req.15 specifies that no image limiting mask shall be used at the exit image location. However, a mask that is oversized is acceptable, and in fact we believe a mask should be used to control stray light. Can Winlight supply a final oversized mask at the output image? It can be sent to us separately, and we could install it after the spectrometer alignment is finished. | Winlight could provide a final oversized mask at the output image with a mounting interface compatible with this accommodation of the pinholes (see question 4). However in that case the oversized mask at intermediate image is no longer useful thus I suggest to remove it and to black paint all the front faces of the spacers that hold the slicer mirrors. | Thank you for adding the mask at the output image. However, I think that keeping the mask at the intermediate image might still be helpful for stray light, and is a good standard practice. Is it difficult to keep the intermediate image mask? | ||
| 6 | OK for CDR Still some work to do to finalize stray light masks and locations. | The analysis of Req.15 (page 26) says that a pupil mask before the second relay mirror is possible, but it is not included in the design. It seems that this is useful to control stray light. Why is this pupil mask not included? We suggest that the mask attached to the slicer mirrors for the first slit image might be extended to allow for masking very near the relay pupil and also the final image – see the attached drawing. Another possibility is that the pupil mask could be added to the final mask at the output image. | The utility of the pupil mask before the output triplet in the photometry path is not proven yet but we could add this pupil mask in case of. | Thank you. It is true that the utility is not proven, but putting a mask at a pupil is a good standard practice. | ||
| 7 | OK for CDR Updated file to be sent later by WL. | In the non-sequential Zemax model, the cal fiber diameter should be 120 microns, not 100. | I will update the size of the calibration fiber in the Nonsequential Zemax model. | Thank you. | ||
| 8 | OK | In many layout diagrams in the reports, the old optical design that uses magnification=10 is shown. For example, page 5 on the optical DJD. It would prevent confusion in the future if the figures matches the current magnification=8 design. | The layout has been updated in the issue C of the optical DJD (WO4681-001-DJD001). | Thank you. For these updates, will you send us the updated documents and models soon? | ||
| 9 | - | Attachment 1: | ||||
| 10 | - | Attachment 2: |
KPF Compliance Matrix (CDR Close-out)
Ref | KPF Requirement Topic | KPF Requirement Text | WL Report | WL CDR | KPF | KPF Lead CDR Sign-off: | KPF Notes |
|---|---|---|---|---|---|---|---|
1 | Bandpass | The operational waveband is 445 to 870 nm, for all fibers. | Optical | YES | Steve | OK | OK: Latest WL Zemax file (RD1) has wavelengths 445-870m. Some throughput analysis curves end at 860 nm, but no large deviation or change from trend expected between 860 nm and 870 nm. |
2 | Input fiber sizes and arrangement | The sizes of the three input fibers and their positions are defined in the accompanying documents. The science fiber, sky fiber, and cal fiber are all octagonal fibers. (The accompanying documents may show the cal fiber as being circular, which is incorrect.) | Optical | YES | Steve | OK | Science fiber fields: OK Cal fiber fields: OK (undersized to account for spot blur at slicer mirror) Photometry fields: OK (updated since CDR) |