Abstract
A polarisation-insensitive transmission trap detector was constructed from two identical polarisation-dependent transmission trap detectors, each containing four 10 mm × 10 mm silicon photodiodes. The performance of the 8-element polarisation-independent and coaxial input-output transmission trap detector has been characterised at laser wavelengths of 635 nm and 850 nm. The measured transmittances are lower than 10−4 and are in agreement with values calculated from the reflectances of single photodiodes. The measured relative transmittances and responsivities are independent of polarisation within 0.12%. The spectral responsivity is spatially uniform within 0.1% across an area of 4 mm × 4 mm , consistent with the expected variations due to the oxide layer thickness of the photodiodes.
| Original language | English |
|---|---|
| Article number | 015008 |
| Journal | Metrologia |
| Volume | 62 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1 Feb 2025 |
| MoE publication type | A1 Journal article-refereed |
Funding
The work leading to this study was funded by the European Metrology Programme for Innovation and Research (EMPIR) Project 14IND05 Optical metrology for quantum-enhanced secure telecommunication (MIQC2). The EMPIR initiative is co-funded by the European Union's Horizon 2020 research and innovation programme and the EMPIR Participating States. The work is part of the Research Council of Finland Flagship Programme, Photonics Research and Innovation (PREIN), Decision Number 346529, Aalto University.
Keywords
- high optical attenuation
- metrology
- photodetectors
- radiometry
- transmission trap detector
- trap detectors