Scattering loss measurement of SOI waveguides using 5X17 integrated optical star coupler
Bibliographic record
Abstract
We describe a novel non-destructive technique to measure the sidewall roughness induced scattering loss of SOI ridge waveguides using an integrated 5x17 star coupler. The accuracy of our technique is independent of the coupling efficiency. In our technique, we capture the near field images of the full output waveguides array with varying width ranging from 0.2 to 2.0 micron and use the intensity maps of these images to produce normalized intensity profiles, from which the relative scattering losses of output waveguides are extracted. Using our technique, we have studied and compared the scattering and polarization dependent losses of three different sets of SOI waveguide samples fabricated by different processes. We have determined the root-mean-square roughness and autocorrelation length of these samples using scanning electron microscopy (SEM). Relating the loss and roughness analysis, we have showed that the process utilizing negative e-beam photoresist and Cr-hardmask with inductively coupled plasma (ICP) etching produced the smoothest waveguide sidewalls and lowest scattering losses. We have also successfully modeled the measured ridge waveguide losses as a function of waveguide width and demonstrated that the theoretical sidewall roughness is in reasonable agreement with the measured roughness from SEM. Our technique is capable of studying roughness induced scattering loss and thus provides an efficient way of optimizing and monitoring process parameters that affect sidewall roughness.
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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 | 0.003 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 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".