Narrow-linewidth three-electrode regrowth-free semiconductor DFB lasers with uniform surface grating
Bibliographic record
Abstract
There has been much interest in developing low-cost laser sources for applications such as photonics integrated circuits and advanced coherent optical communications. The ultimate objectives in this development include wide wavelength tunability, a narrow linewidth, and an ease of integration with other devices. For this purpose, semiconductor surface grating distributed feedback (SG-DFB) lasers have been introduced. SG-DFB manufacturing consists of a unique sequence of planar epitaxial growth resulting in a major simplification to the fabrication process. SG-DFB lasers are highly monolithically integrate-able with other devices due to their small footprint. The segmentation of the built-in top electrode helps to alleviate the adverse spatial-hole burning effects encountered in single-electrode devices and brings hence significant enhancements to the laser performance. For the first time, we report here on the design, fabrication, and characterization of InGaAsP/InP multiple-quantum-well (MQW) SG-DFB lasers with uniform third-order surface grating etched by means of stepper lithography and inductively-coupled reactive-ion. The uncoated device reported here is 750 μm-long SG-DFB laser whose central and lateral top electrodes are 244 μmlongs each, separated by two 9 μm-long grooves. The experimental characterization shows stable single mode operation at room temperature under uniform and non-uniform injection. High side mode suppression ratios (SMSRs) (50-55dB) under a wide range of injection current have been discerned as well. A relatively broad wavelength tuning (<4nm) has also been observed. Moreover, a narrow linewidth (<300 kHz) has been recorded for different injection currents.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 | 0.001 | 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 source (direct Gemma or distilled Codex), 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".