Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Conference on Lasers and Electro-Optics

Coherence property of time-multiplexed degenerate optical parametric oscillator pulses generated using a nonlinear fiber Sagnac loop

Hsin-Pin Lo, Takahiro Inagaki, Toshimori Honjo, Hiroki Takesue

Published Jan 1, 2020• 0 citations
Publisher

Abstract

We generated time-multiplexed degenerate optical parametric oscillator pulses using a nonlinear fiber Sagnac interferometer. We confirmed that the phases of pulses were bifurcated to 0 or n, which makes them useful for simulating Ising spins.
DOI
10.1364/cleo_si.2020.sm1l.5

Related papers

Network of femtosecond degenerate OPOs for solving NP-Hard Ising problems

Alireza Marandi, Kenta Takata, Zhe Wang +2 more

We report implementation of a configurable network of four degenerate optical parametric oscillators as an Ising spin system using time-multiplexed femtosecond pulses. This coherent Ising machine solves an instance of NP-hard MAXCUT problem without error.

•Jan 1, 2014•0 citations

Experimental research on generating and splitting degenerate correlated photon pairs in Sagnac fiber loop

Yang Lei, Liu Nan-Nan, Xiaoying Li

Degenerate correlated photon pairs (DCPPs) have been widely used in quantum information science,especially in the areas of quantum computation,quantum state control and precision measurement,which are typically generated in a (2) nonlinear crystal through the spontaneous parametric down-conversion.However,such a source is not compatible with optical fiber as large coupling losses occur when the pairs are launched into it,which restricts its direct application to quantum information processing system.More recently,DCPP generation from spontaneous four-wave mixing in (3) optical fiber has aroused strong interest,due to its advantages of compatibility with existing fiber networks and free of alignment.The process of generating DCPP in fiber can be described as follows:two pump photons at different frequencies p1 and p2 scatter through the (3) nonlinearity to create a pair of identical photons at the mean frequency c,such that p1+p2=2c.Because the collinear tensor component xxxx(3) in a Kerr nonlinear medium is 3 times as large as the tensor component xyxy(3),the co-polarized four-wave mixing is preferred,which means the two pump photons and new-born twin photons are both co-polarized.Therefore,it is very challenging to deterministically separate the fiber-based DCPP,since the twin photons share the same properties in all degrees of freedom:frequency,polarization and spatial.Sagnac fiber loop (SFL),composed of a piece of nonlinear fiber and 50/50 coupler,is presented as the splitter for DCPP based on the reversed Hong-Ou-Mandel quantum interference of counter-propagating DCPPs.The SFL can be configured as a total reflector,total transmitter or equally transmissive and reflective state,which sets the differential phases of counter-propagating DCPPs meeting at 50/50 coupler to be ,0 and -,respectively.In order to satisfy the differential phase requirement for completely splitting the DCPP,the SFL is always set to be equally transmissive and reflective state,however,the polarization-mode matching of counter-propagating DCPPs is not easily achieved due to the disturbance of fiber birefringence.According to the Jones matrix derivation of DCPP propagating in the SFL,the polarization mode of counter-propagating DCPPs when interference at 50/50 coupler is automatically matched,if the SFL is set as a total reflector or total transmitter.In experimental scheme,utilizing the SFL as a total reflector,the 1.1 nm bandwidth and 1544.53 nm central wavelength DCPPs are generated by two pulsed light beams pumping the 300 m dispersion-shifted fiber in the SFL.Using the two pieces of single mode fiber connecting the 300 m dispersion-shifted fiber and 50/50 coupler,whose length difference is fixed at 3.3 m,the differential phase of counter-propagating DCPPs highly dependent on the dispersion properties of single mode fiber is managed at 2 for fully distributing DCPPs into which degrades the fidelity of DCPP source.The measured ratio of coincidence to accidental-coincidence of DCPPs from one port is approximately 1.8:1,which indicates that the coincidence counts mainly originate from accidental coincidence counts and extra coincidence counts from photon bunching and there are not any DCPPs outputting from one port.Meanwhile,the ratio of best measured coincidence to accidental-coincidence of DCPPs from two ports reaches 47:1,when the average power of two pumps is fixed at 0.026 mW.The experimental results demonstrate that the high purity and fully spatial separation DCPPs are successfully prepared in optical fibers,which is a very useful tool for realizing various quantum information systems.How the spatial state of outputting DCPPs depends on the length difference between single-mode fiber and detuning wavelength is also discussed in detail.

Acta Physica Sinica•Jan 1, 2016•2 citations

10-GHz-clock time-multiplexed non-degenerate optical parametric oscillator network with a variable planar lightwave circuit interferometer

Yuya Yonezu, Kensuke Inaba, Yasuhiro Yamada +4 more

A coherent XY machine (CXYM) is a physical spin simulator that can simulate the XY model by mapping XY spins onto the continuous phases of non-degenerate optical parametric oscillators (NOPOs). Here, we demonstrated a large-scale CXYM with >47,000 spins by generating 10-GHz-clock time-multiplexed NOPO pulses via four-wave mixing in a highly nonlinear fiber inside a fiber ring cavity. By implementing a unidirectional coupling from the ith pulse to the (i + 1)th pulse with a variable 1-pulse delay planar lightwave circuit interferometer, we successfully controlled the effective temperature of a one-dimensional XY spin network within two orders of magnitude.

arXiv:2307.03333•Optics Letters•Oct 6, 2023•5 citations

Coherent Ising machine based on polarization symmetry breaking in a driven Kerr resonator

Liam Quinn, Yiqing Xu, Julien Fatome +4 more

Time-multiplexed networks of degenerate optical parametric oscillators have demonstrated remarkable success in simulating coupled Ising spins, thus providing a promising route to solving complex combinatorial optimization problems. In these systems, referred to as coherent Ising machines, spins are encoded in the oscillator phases, and measured at the system output using phase-sensitive techniques, making intricate phase stabilization necessary. Here, we introduce an optical Ising machine based on spontaneous polarization symmetry breaking in a coherently driven fiber Kerr nonlinear resonator. In our architecture, the spins are encoded in the polarization state, allowing robust, all-intensity readout with off-the-shelf telecom components. By operating in a newly-discovered regime where nonlinearity and topology lock the system's symmetry, we eliminate drift and bias, enabling uninterrupted Ising trials at optical speeds for over an hour, without manual intervention. This all-fiber platform not only simplifies the hardware but also opens a path to more stable, high-throughput coherent optical optimization devices for applications from finance to drug design and beyond.

Nature Communications•Jan 28, 2026•5 citations

Quantum soliton generation via interference of nonlinear Schrodinger equation coherent solitonic fields

M.J. Werner, Stephen R. Friberg

Summary form only given. We have shown for the first time that large photon-number squeezing of coherent pulses can be produced by a Sagnac loop for a significant range of input energies and that it is larger than predicted for directly spectrally filtered optical fiber solitons. Despite this, we pointed out the similarities between the two schemes. In essence, a Sagnac fiber loop is capable of producing optical pulses closer to true quantum solitons than their coherent counterparts from modelocked lasers.

Conference on Lasers and Electro-Optics•Nov 27, 2002•1 citation

An Ultrafast Source of Polarization Entangled Photon Pairs based on a Sagnac Interferometer

Devin H. Smith

This thesis describes the design, development, and implementation of a pulsed source of polarization-entangled photons using spontaneous parametric down-conversion in a Sagnac interferometer. A tangle of 0.9286 ± 0.0015, fidelity to the state (|10〉 + |01〉)/√2 of \n0.9798 ± 0.0004 and a brightness of 597 pairs/s/mW were demonstrated. \n \nSpontaneous parametric down-conversion is a nonlinear optical process in which one photon is split into two lower-frequency photons while conserving momentum and energy, in this \nexperiment nearly degenerate photons are produced. These photons are then interfered at the output beamsplitter of the interferometer, exchanging path entanglement for polarization entanglement and generating the desired polarization-entangled photon pairs.

•Jan 26, 2009•1 citation
Degenerate correlated photon pairs (DCPPs) have been widely used in quantum information science,especially in the areas of quantum computation,quantum state control and precision measurement,which are typically generated in a (2) nonlinear crystal through the spontaneous parametric down-conversion.However,such a source is not compatible with optical fiber as large coupling losses occur when the pairs are launched into it,which restricts its direct application to quantum information processing system.More recently,DCPP generation from spontaneous four-wave mixing in (3) optical fiber has aroused strong interest,due to its advantages of compatibility with existing fiber networks and free of alignment.The process of generating DCPP in fiber can be described as follows:two pump photons at different frequencies p1 and p2 scatter through the (3) nonlinearity to create a pair of identical photons at the mean frequency c,such that p1+p2=2c.Because the collinear tensor component xxxx(3) in a Kerr nonlinear medium is 3 times as large as the tensor component xyxy(3),the co-polarized four-wave mixing is preferred,which means the two pump photons and new-born twin photons are both co-polarized.Therefore,it is very challenging to deterministically separate the fiber-based DCPP,since the twin photons share the same properties in all degrees of freedom:frequency,polarization and spatial.Sagnac fiber loop (SFL),composed of a piece of nonlinear fiber and 50/50 coupler,is presented as the splitter for DCPP based on the reversed Hong-Ou-Mandel quantum interference of counter-propagating DCPPs.The SFL can be configured as a total reflector,total transmitter or equally transmissive and reflective state,which sets the differential phases of counter-propagating DCPPs meeting at 50/50 coupler to be ,0 and -,respectively.In order to satisfy the differential phase requirement for completely splitting the DCPP,the SFL is always set to be equally transmissive and reflective state,however,the polarization-mode matching of counter-propagating DCPPs is not easily achieved due to the disturbance of fiber birefringence.According to the Jones matrix derivation of DCPP propagating in the SFL,the polarization mode of counter-propagating DCPPs when interference at 50/50 coupler is automatically matched,if the SFL is set as a total reflector or total transmitter.In experimental scheme,utilizing the SFL as a total reflector,the 1.1 nm bandwidth and 1544.53 nm central wavelength DCPPs are generated by two pulsed light beams pumping the 300 m dispersion-shifted fiber in the SFL.Using the two pieces of single mode fiber connecting the 300 m dispersion-shifted fiber and 50/50 coupler,whose length difference is fixed at 3.3 m,the differential phase of counter-propagating DCPPs highly dependent on the dispersion properties of single mode fiber is managed at 2 for fully distributing DCPPs into which degrades the fidelity of DCPP source.The measured ratio of coincidence to accidental-coincidence of DCPPs from one port is approximately 1.8:1,which indicates that the coincidence counts mainly originate from accidental coincidence counts and extra coincidence counts from photon bunching and there are not any DCPPs outputting from one port.Meanwhile,the ratio of best measured coincidence to accidental-coincidence of DCPPs from two ports reaches 47:1,when the average power of two pumps is fixed at 0.026 mW.The experimental results demonstrate that the high purity and fully spatial separation DCPPs are successfully prepared in optical fibers,which is a very useful tool for realizing various quantum information systems.How the spatial state of outputting DCPPs depends on the length difference between single-mode fiber and detuning wavelength is also discussed in detail.
A coherent XY machine (CXYM) is a physical spin simulator that can simulate the XY model by mapping XY spins onto the continuous phases of non-degenerate optical parametric oscillators (NOPOs). Here, we demonstrated a large-scale CXYM with >47,000 spins by generating 10-GHz-clock time-multiplexed NOPO pulses via four-wave mixing in a highly nonlinear fiber inside a fiber ring cavity. By implementing a unidirectional coupling from the ith pulse to the (i + 1)th pulse with a variable 1-pulse delay planar lightwave circuit interferometer, we successfully controlled the effective temperature of a one-dimensional XY spin network within two orders of magnitude.
Time-multiplexed networks of degenerate optical parametric oscillators have demonstrated remarkable success in simulating coupled Ising spins, thus providing a promising route to solving complex combinatorial optimization problems. In these systems, referred to as coherent Ising machines, spins are encoded in the oscillator phases, and measured at the system output using phase-sensitive techniques, making intricate phase stabilization necessary. Here, we introduce an optical Ising machine based on spontaneous polarization symmetry breaking in a coherently driven fiber Kerr nonlinear resonator. In our architecture, the spins are encoded in the polarization state, allowing robust, all-intensity readout with off-the-shelf telecom components. By operating in a newly-discovered regime where nonlinearity and topology lock the system's symmetry, we eliminate drift and bias, enabling uninterrupted Ising trials at optical speeds for over an hour, without manual intervention. This all-fiber platform not only simplifies the hardware but also opens a path to more stable, high-throughput coherent optical optimization devices for applications from finance to drug design and beyond.
Summary form only given. We have shown for the first time that large photon-number squeezing of coherent pulses can be produced by a Sagnac loop for a significant range of input energies and that it is larger than predicted for directly spectrally filtered optical fiber solitons. Despite this, we pointed out the similarities between the two schemes. In essence, a Sagnac fiber loop is capable of producing optical pulses closer to true quantum solitons than their coherent counterparts from modelocked lasers.
This thesis describes the design, development, and implementation of a pulsed source of polarization-entangled photons using spontaneous parametric down-conversion in a Sagnac interferometer. A tangle of 0.9286 ± 0.0015, fidelity to the state (|10〉 + |01〉)/√2 of \n0.9798 ± 0.0004 and a brightness of 597 pairs/s/mW were demonstrated. \n \nSpontaneous parametric down-conversion is a nonlinear optical process in which one photon is split into two lower-frequency photons while conserving momentum and energy, in this \nexperiment nearly degenerate photons are produced. These photons are then interfered at the output beamsplitter of the interferometer, exchanging path entanglement for polarization entanglement and generating the desired polarization-entangled photon pairs.