GIRMOS image slicer: test plan and characterization
Bibliographic record
Abstract
Image slicers (SLI) are now standard equipment in astronomical instrumentation, particularly for Integral Field Spectroscopy (IFS). Our team at the Advanced Optical Fabrication Infrastructure (AOFI) has been tasked with the fabrication of the slicer-based IFU for GIRMOS (Gemini InfraRed Multi-Object Spectrograph), which contains 42 250-μm wide slices along with the corresponding pupil and field mirrors. Diamond turning image slicers is complicated as they often include tilted slices smaller than 500-μm wide. The surface finish of diamond-turned optics must be optimal in astronomical applications such as integral field spectroscopy. Here we present a test plan and characterization of the GIRMOS SLI system. One notable challenge is the disparity between room temperature testing and the cryogenic environment of the actual system. This requires the design of a warm model, which has been numerically validated. A comprehensive metrology process is implemented, utilizing equipment such as a Talysurf PGI Freeform profilometer, a ZYGO Verifire HD Fizeau interferometer, a coordinate measuring machine (CMM), a point source microscope (PSM) equipped with a motorized gimbal mount, a scanning electron microscope (SEM), and a custom SLI-M1 test bench. The test bench facilitates verification of intermediate pupil positions, calculation of the slices' tilts and curvatures, measurement of diffraction efficiency, and estimation of surface roughness through total integrated scatter (TIS) analysis. Additionally, the bench is used to characterize the pseudo-slit output by replacing front-end optics and enables the measurement of tilts on all surfaces using a precision motorized gimbal stage. The test plan presented establishes a robust methodology for comprehensive characterization, essential for high precision integral field spectroscopy in astronomical observations.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".