Details
| Original language | English |
|---|---|
| Title of host publication | Integrated Optics |
| Subtitle of host publication | Devices, Materials, and Technologies XXIX |
| Editors | Sonia M. Garcia-Blanco, Pavel Cheben |
| Publisher | SPIE |
| ISBN (electronic) | 9781510684867 |
| Publication status | Published - 19 Mar 2025 |
| Event | Integrated Optics: Devices, Materials, and Technologies XXIX 2025 - San Francisco, United States Duration: 27 Jan 2025 → 30 Jan 2025 |
Publication series
| Name | Proceedings of SPIE - The International Society for Optical Engineering |
|---|---|
| Volume | 13369 |
| ISSN (Print) | 0277-786X |
| ISSN (electronic) | 1996-756X |
Abstract
We present an automated active alignment procedure for assembling miniaturized photonic quantum circuits specifically designed to handle single-photon-level signals (i.e. low photon count). This process is exemplarily used for producing a polarization-based encode-and-measure quantum key distribution emitter. For this, we use the integration of miniaturized substrate-free thin-film filter elements into laser-induced deep-etched pockets on a photonic platform. The filter elements function as splitters to combine/divide four beams with different linear polarization states, as required for the BB84 quantum communication protocol. Bare-die laser diodes bonded to the same platform are used to create the single-photon level signals. The single filter chips are placed under an angle of 45 degrees to the propagation direction of the photon radiation vertically into the deep-etched pockets and fixed on the platform surface with UV-curable adhesive. The resulting signal is subsequently coupled into a single-mode fiber. For active alignment, a single photon avalanche detector is used in a feedback loop with a precision-optics assembly system, exploiting six degrees of freedom for the alignment of the assembly with stacked translation and rotation stages. The single photon detector is connected to an oscilloscope where a single voltage peak signals the detection of a photon. Aligning the filter elements changes the number of photons detected. The average voltage is a measure for the number of photons detected per integration time and used for the active alignment loop. This technique enables the active alignment of optical components for single photon-level signals, otherwise not detectable with conventional power meters.
Keywords
- Automated Assembly, BB84 Protocol, Hybrid Photonic Integration, Optical Alignment, Quantum Cryptography, Quantum Key Distribution, Secure Communication, Substrate-free Thin Film Filters
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Physics and Astronomy(all)
- Condensed Matter Physics
- Computer Science(all)
- Computer Science Applications
- Mathematics(all)
- Applied Mathematics
- Engineering(all)
- Electrical and Electronic Engineering
Cite this
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Integrated Optics: Devices, Materials, and Technologies XXIX. ed. / Sonia M. Garcia-Blanco; Pavel Cheben. SPIE, 2025. 133690Z (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 13369).
Research output: Chapter in book/report/conference proceeding › Conference contribution › Research › peer review
}
TY - GEN
T1 - Automatic active alignment of substrate-free thin-film filters on a photonic platform using single photon detectors
AU - Gehrke, P.
AU - Rüsseler, A. K.
AU - Matthes, J.
AU - Fütterer, L.
AU - Raffalt, E.
AU - Günther, A.
AU - Johanning, R.
AU - Hoffmann, G. A.
AU - Wienke, A.
AU - Kracht, D.
AU - Kues, M.
N1 - Publisher Copyright: © 2025 SPIE.
PY - 2025/3/19
Y1 - 2025/3/19
N2 - We present an automated active alignment procedure for assembling miniaturized photonic quantum circuits specifically designed to handle single-photon-level signals (i.e. low photon count). This process is exemplarily used for producing a polarization-based encode-and-measure quantum key distribution emitter. For this, we use the integration of miniaturized substrate-free thin-film filter elements into laser-induced deep-etched pockets on a photonic platform. The filter elements function as splitters to combine/divide four beams with different linear polarization states, as required for the BB84 quantum communication protocol. Bare-die laser diodes bonded to the same platform are used to create the single-photon level signals. The single filter chips are placed under an angle of 45 degrees to the propagation direction of the photon radiation vertically into the deep-etched pockets and fixed on the platform surface with UV-curable adhesive. The resulting signal is subsequently coupled into a single-mode fiber. For active alignment, a single photon avalanche detector is used in a feedback loop with a precision-optics assembly system, exploiting six degrees of freedom for the alignment of the assembly with stacked translation and rotation stages. The single photon detector is connected to an oscilloscope where a single voltage peak signals the detection of a photon. Aligning the filter elements changes the number of photons detected. The average voltage is a measure for the number of photons detected per integration time and used for the active alignment loop. This technique enables the active alignment of optical components for single photon-level signals, otherwise not detectable with conventional power meters.
AB - We present an automated active alignment procedure for assembling miniaturized photonic quantum circuits specifically designed to handle single-photon-level signals (i.e. low photon count). This process is exemplarily used for producing a polarization-based encode-and-measure quantum key distribution emitter. For this, we use the integration of miniaturized substrate-free thin-film filter elements into laser-induced deep-etched pockets on a photonic platform. The filter elements function as splitters to combine/divide four beams with different linear polarization states, as required for the BB84 quantum communication protocol. Bare-die laser diodes bonded to the same platform are used to create the single-photon level signals. The single filter chips are placed under an angle of 45 degrees to the propagation direction of the photon radiation vertically into the deep-etched pockets and fixed on the platform surface with UV-curable adhesive. The resulting signal is subsequently coupled into a single-mode fiber. For active alignment, a single photon avalanche detector is used in a feedback loop with a precision-optics assembly system, exploiting six degrees of freedom for the alignment of the assembly with stacked translation and rotation stages. The single photon detector is connected to an oscilloscope where a single voltage peak signals the detection of a photon. Aligning the filter elements changes the number of photons detected. The average voltage is a measure for the number of photons detected per integration time and used for the active alignment loop. This technique enables the active alignment of optical components for single photon-level signals, otherwise not detectable with conventional power meters.
KW - Automated Assembly
KW - BB84 Protocol
KW - Hybrid Photonic Integration
KW - Optical Alignment
KW - Quantum Cryptography
KW - Quantum Key Distribution
KW - Secure Communication
KW - Substrate-free Thin Film Filters
UR - http://www.scopus.com/inward/record.url?scp=105002369051&partnerID=8YFLogxK
U2 - 10.1117/12.3042937
DO - 10.1117/12.3042937
M3 - Conference contribution
AN - SCOPUS:105002369051
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Integrated Optics
A2 - Garcia-Blanco, Sonia M.
A2 - Cheben, Pavel
PB - SPIE
T2 - Integrated Optics
Y2 - 27 January 2025 through 30 January 2025
ER -