Erbium-ytterbium co-doped aluminium oxide waveguide amplifiers fabricated by reactive co-sputtering and wet chemical etching
Bibliographic record
Abstract
We report on the fabrication and optical characterization of erbium-ytterbium co-doped aluminum oxide (Al 2 O 3 :Er 3+ :Yb 3+ ) waveguides using low-cost, low-temperature deposition and etching steps. We deposited Al 2 O 3 :Er 3+ :Yb 3+ films using reactive co-sputtering, with Er 3+ and Yb 3+ ion concentrations ranging from 1.4–1.6 × 10 20 and 0.9–2.1 × 10 20 ions/cm 3 , respectively. We etched ridge waveguides in 85% pure phosphoric acid at 60°C, allowing for structures with minimal polarization sensitivity and acceptable bend radius suitable for optical amplifiers and avoiding alternative etching chemistries which use hazardous gases. Scanning-electron-microscopy (SEM) and profilometry were used to assess the etch depth, sidewall roughness, and facet profile of the waveguides. The Al 2 O 3 :Er 3+ :Yb 3+ films exhibit a background loss as low as 0.2 ± 0.1 dB/cm and the waveguide loss after structuring is determined to be 0.5 ± 0.3 dB/cm at 1640 nm. Internal net gain of 4.3 ± 0.9 dB is demonstrated at 1533 nm for a 3.0 cm long waveguide when pumped at 970 nm. The material system is promising moving forward for compact Er-Yb co-doped waveguide amplifiers and lasers on a low-cost silicon wafer-scale platform.
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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".