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

arXiv:1210.6137 · Optics Express

Noncollinear parametric fluorescence by chirped quasi-phase matching for monocycle temporal entanglement

Akira Tanaka, Ryo Okamoto, Hwan Hong Lim, Shanthi Subashchandran, Masayuki Okano, Labao Zhang, Lin Kang, Jian Chen, Peiheng Wu, Toru Hirohata, Sunao Kurimura, Shigeki Takeuchi

Published Oct 22, 2012• 65 citations
arXivHTMLPDF

Abstract

Quantum entanglement of two photons created by spontaneous parametric downconversion (SPDC) can be used to probe quantum optical phenomena during a single cycle of light. Harris [Opt. Express 98, 063602 (2007)] suggested using ultrabroad parametric fluorescenc generated from a quasi-phase-matched (QPM) device whose poling period is chirped. In the Harris's original proposal, it is assumed that the photons are collinearly generated and then spatially separated by frequency filtering Here, we alternatively propose using noncollinearly generated SPDC. In our numerical calculation, to achieve 1.2 cycle temporal correlation for a 532 nm pump laser, only 10% -chirped device is sufficien when noncollinear condition is applied, while a largely chirped (50%) device is required in collinear condition. We also experimentally demonstrate an octave-spanning (790-1610 nm) noncollinear parametric fluorescenc from a 10% chirped MgSLT crystal using both a superconducting nanowire single-photon detector and photomultiplier tube as photon detectors. The observed SPDC bandwidth is 194 THz, which is the largest width achieved to date for a chirped QPM device. From this experimental result, our numerical analysis predicts that the bi-photon can be compressed to 1.2 cycles with appropriate phase compensation.

DOI
10.1364/oe.20.025228

Related papers

Collinear ultra-broadband parametric fluorescence generated from 10%-chirped quasi phase matched device

Akira Tanaka, Ryo Okamoto, Hwan Hong Lim +4 more

The state-of-art technology of a quasi-phase matched (QPM) device has enabled the efficient generation of frequency-entangled photon pairs through parametric fluorescence [1, 2]. Harris [3] has proposed the generation of photon pairs which are correlated on a mono-cycle time scale of optical period. In that paper, the poling period of QPM device is linearly chirped (increased) from the entrance to the exit. Thus, each poling period is phase matched at different wavelengths of photon pairs, spanning ultra-broad spectrum. Recent experiment by Mohan et al as its application to quantum optical coherence tomography [4], has realized the parametric fluorescence from chirped-QPM device which is phase matched from 820nm to 1500nm using stoichiometric lithium tantalate (SLT) crystal as a nonlinear medium with 13% chirping (poling period: from 7.500µm to 8.500µm).

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•May 1, 2011•1 citation

Spectral properties of ultra-broadband entangled photons generated from chirped-MgSLT crystal towards monocycle entanglement generation

Akira Tanaka, Ryo Okamoto, Hwan Hong Lim +9 more

Compressing the temporal correlation of two photons to the monocycle regime (3.56 fs, center wavelength: 1064 nm) is expected to open up new perspectives in quantum metrology, allowing applications such as submicron quantum optical coherence tomography and novel nonlinear optical experiments. To achieve this, the two-photon state must essentially be ultra-broadband in the frequency domain and ultra-short in the time domain. Here, we report the successful generation of such ultra-broadband, frequency-correlated two-photon states via type-0, cw-pumped (532 nm) spontaneous parametric down conversion using four PPMgSLT crystals with different chirp rates of their poling periods. For the collinear condition, single-photon spectra are detected using a Si-CCD and an InGaAs photodiode array with a monochromator, while for a noncollinear condition, an NbN meander-type superconducting single photon detector (SNSPD) and an InP/GaAs photomultiplier tube (PMT) with a laser line Bragg tunable bandpass filter are used. The broadband sensitivity of the SNSPD and PMT in the near-infrared wavelength range enable singleshot observations with a maximum bandwidth of 820 nm among the four samples. Such spectra can in principle achieve a temporal correlation as short as 1.2 cycles (4.4 fs) with the use of appropriate phase compensation, which can be measured using the sum-frequency signal. We also discuss several detection strategies for measuring coincidence counts in the presence of wavelength-dependent optical elements as a step towards frequency correlation measurements.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Mar 29, 2013•1 citation

The single-cycle biphotons generated by SPDC in chirped QPM PPKTP crystal

Wang Jinbao, Lin Haibo

In this paper, we have studied the process of monochromatic pump light in linearly chirped Periodically Poled [Formula: see text] (PPKTP) nonlinear crystal to generate single-cycle biphotons under Quasi-Phase-Matching (QPM) conditions through a Spontaneous Parametric Down-Conversion (SPDC). A detailed analysis of the phase mismatching function reveals that in PPKTP crystals, for the proper frequency range, the phase mismatching [Formula: see text] is stable and relatively close to 0 due to the relatively stable refractive index, and therefore has a good phase matching effect. Even when the chirp rate becomes small, it is able to produce single-cycle biphotons due to the near-perfect phase matching. Of course, as the chirp rate increases, the frequency response range becomes wider, the temporal width is narrower, and the number of cycles is smaller.

Journal of Nonlinear Optical Physics & Materials•Feb 18, 2024•0 citations

Non-collinear generation of ultra-broadband parametric fluorescence photon pairs using chirped quasi-phase matching slab waveguides

Bo Cao, Kyohei Hayama, Shun Suezawa +5 more

Many optical quantum applications rely on broadband frequency correlated photon pair sources. We previously reported a scheme for collinear emission of high-efficiency and ultra-broadband photon pairs using chirped quasi-phase matching (QPM) periodically poled stoichiometric lithium tantalate (PPSLT) ridge waveguides. However, collinearly emitted photon pairs cannot be directly adopted for applications that are based on two-photon interference, such as quantum optical coherence tomography (QOCT). In this work, we developed a chirped QPM device with a slab waveguide structure. This device was designed to produce spatially separable (photon pair non-collinear emission) parametric fluorescence photon pairs with an ultra-broadband bandwidth in an extremely efficient manner. Using a non-chirped QPM slab waveguide, we observed a photon pair spectrum with a full-width-at-half-maximum (FWHM) bandwidth of 26 nm. When using a 3% chirped QPM slab waveguide, the FWHM bandwidth of the spectrum increased to 190 nm, and the base-to-base width is 308 nm. We also confirmed a generation efficiency of 2.4×10 6 pairs/( μ W·s) using the non-chirped device, and a efficiency of 8×10 5 pairs/( μ W·s) using the 3% chirped device under non-collinear emission conditions after single-mode fiber coupling. This is, to the best of our knowledge, the first report of frequency correlated photon pairs generation using slab waveguide device as a source. In addition, using slab waveguides as photon pair sources, we performed two-photon interference experiments with the non-chirped device and obtained a Hong–Ou–Mandel (HOM) dip with a FWHM of 7.7 μ m and visibility of 98%. When using the 3% chirped device as photon pair source, the HOM measurement gave a 2 μ m FWHM dip and 74% visibility.

Optics Express•May 22, 2023•9 citations

The temperature-dependent in noncollinear SPDC for generating biphotons with single cycles

Lin Haibo, Wang Jinbao

The influence of temperature on generating single cycle biphotons by noncollinear spontaneous parametric down-conversion (SPDC) in chirped quasi-phase-matching (QPM) periodically poled lithium niobate (PPLN) crystal have been studied in this paper. Numerical simulation shows that characteristics of the biphotons are mainly determined by the phase matching function which is dependent on the angle of the noncollinear SPDC and the temperature of the nonlinear crystal. Moreover, the angle plays a more significant role in noncollinear SPDC. The smaller angle and lower temperature can produce better phase matching effect while the angle and temperature changes within an appropriate range. The count rate of the biphotons will decrease, the bandwidth of biphotons will be compressed and the temporal width is widened for a certain appropriate angle in noncollinear SPDC while temperature is increased. However, as long as the angle and temperature are suitable, the biphotons generated by SPDC in the chirped QPM PPLN crystal are ultrashort pulses with single cycles.

Journal of the European Optical Society Rapid Publications•Jan 1, 2025•0 citations

The single-cycle biphotons generated by noncollinear SPDC in the chirped QPM crystals

Jinbao Wang, Haibo Lin

We analysis the noncollinear Spontaneous Parametric Down Conversion (SPDC) and compare the biphotons generated by the chirped Quasi-Phase-Matching (QPM) between the Periodically Poled Lithium Niobate (PPLN) and Periodically Poled KTiOPO4 (PPKTP) crystals. Due to the chirping of the crystals, the frequency response range of the biphotons would be greatly increased. For nonlinear SPDC, angular variation is limited (less than 0.06° in this paper), and the angle would narrow the frequency response range of the biphotons. We compare the effect of angle in PPLN crystals and PPKTP crystals for biphotons. Both the two crystals with chirped QPM, the single-cycle biphotons can be generated during noncollinear SPDC within a suitable angle range, which is favorable for wider applications in experiments.

Journal of the European Optical Society Rapid Publications•Jan 1, 2024•2 citations
Quantum entanglement of two photons created by spontaneous parametric downconversion (SPDC) can be used to probe quantum optical phenomena during a single cycle of light. Harris [Opt. Express 98, 063602 (2007)] suggested using ultrabroad parametric fluorescenc generated from a quasi-phase-matched (QPM) device whose poling period is chirped. In the Harris's original proposal, it is assumed that the photons are collinearly generated and then spatially separated by frequency filtering Here, we alternatively propose using noncollinearly generated SPDC. In our numerical calculation, to achieve 1.2 cycle temporal correlation for a 532 nm pump laser, only 10% -chirped device is sufficien when noncollinear condition is applied, while a largely chirped (50%) device is required in collinear condition. We also experimentally demonstrate an octave-spanning (790-1610 nm) noncollinear parametric fluorescenc from a 10% chirped MgSLT crystal using both a superconducting nanowire single-photon detector and photomultiplier tube as photon detectors. The observed SPDC bandwidth is 194 THz, which is the largest width achieved to date for a chirped QPM device. From this experimental result, our numerical analysis predicts that the bi-photon can be compressed to 1.2 cycles with appropriate phase compensation.
The state-of-art technology of a quasi-phase matched (QPM) device has enabled the efficient generation of frequency-entangled photon pairs through parametric fluorescence [1, 2]. Harris [3] has proposed the generation of photon pairs which are correlated on a mono-cycle time scale of optical period. In that paper, the poling period of QPM device is linearly chirped (increased) from the entrance to the exit. Thus, each poling period is phase matched at different wavelengths of photon pairs, spanning ultra-broad spectrum. Recent experiment by Mohan et al as its application to quantum optical coherence tomography [4], has realized the parametric fluorescence from chirped-QPM device which is phase matched from 820nm to 1500nm using stoichiometric lithium tantalate (SLT) crystal as a nonlinear medium with 13% chirping (poling period: from 7.500µm to 8.500µm).
Compressing the temporal correlation of two photons to the monocycle regime (3.56 fs, center wavelength: 1064 nm) is expected to open up new perspectives in quantum metrology, allowing applications such as submicron quantum optical coherence tomography and novel nonlinear optical experiments. To achieve this, the two-photon state must essentially be ultra-broadband in the frequency domain and ultra-short in the time domain. Here, we report the successful generation of such ultra-broadband, frequency-correlated two-photon states via type-0, cw-pumped (532 nm) spontaneous parametric down conversion using four PPMgSLT crystals with different chirp rates of their poling periods. For the collinear condition, single-photon spectra are detected using a Si-CCD and an InGaAs photodiode array with a monochromator, while for a noncollinear condition, an NbN meander-type superconducting single photon detector (SNSPD) and an InP/GaAs photomultiplier tube (PMT) with a laser line Bragg tunable bandpass filter are used. The broadband sensitivity of the SNSPD and PMT in the near-infrared wavelength range enable singleshot observations with a maximum bandwidth of 820 nm among the four samples. Such spectra can in principle achieve a temporal correlation as short as 1.2 cycles (4.4 fs) with the use of appropriate phase compensation, which can be measured using the sum-frequency signal. We also discuss several detection strategies for measuring coincidence counts in the presence of wavelength-dependent optical elements as a step towards frequency correlation measurements.
In this paper, we have studied the process of monochromatic pump light in linearly chirped Periodically Poled [Formula: see text] (PPKTP) nonlinear crystal to generate single-cycle biphotons under Quasi-Phase-Matching (QPM) conditions through a Spontaneous Parametric Down-Conversion (SPDC). A detailed analysis of the phase mismatching function reveals that in PPKTP crystals, for the proper frequency range, the phase mismatching [Formula: see text] is stable and relatively close to 0 due to the relatively stable refractive index, and therefore has a good phase matching effect. Even when the chirp rate becomes small, it is able to produce single-cycle biphotons due to the near-perfect phase matching. Of course, as the chirp rate increases, the frequency response range becomes wider, the temporal width is narrower, and the number of cycles is smaller.
Many optical quantum applications rely on broadband frequency correlated photon pair sources. We previously reported a scheme for collinear emission of high-efficiency and ultra-broadband photon pairs using chirped quasi-phase matching (QPM) periodically poled stoichiometric lithium tantalate (PPSLT) ridge waveguides. However, collinearly emitted photon pairs cannot be directly adopted for applications that are based on two-photon interference, such as quantum optical coherence tomography (QOCT). In this work, we developed a chirped QPM device with a slab waveguide structure. This device was designed to produce spatially separable (photon pair non-collinear emission) parametric fluorescence photon pairs with an ultra-broadband bandwidth in an extremely efficient manner. Using a non-chirped QPM slab waveguide, we observed a photon pair spectrum with a full-width-at-half-maximum (FWHM) bandwidth of 26 nm. When using a 3% chirped QPM slab waveguide, the FWHM bandwidth of the spectrum increased to 190 nm, and the base-to-base width is 308 nm. We also confirmed a generation efficiency of 2.4×10 6 pairs/( μ W·s) using the non-chirped device, and a efficiency of 8×10 5 pairs/( μ W·s) using the 3% chirped device under non-collinear emission conditions after single-mode fiber coupling. This is, to the best of our knowledge, the first report of frequency correlated photon pairs generation using slab waveguide device as a source. In addition, using slab waveguides as photon pair sources, we performed two-photon interference experiments with the non-chirped device and obtained a Hong–Ou–Mandel (HOM) dip with a FWHM of 7.7 μ m and visibility of 98%. When using the 3% chirped device as photon pair source, the HOM measurement gave a 2 μ m FWHM dip and 74% visibility.
The influence of temperature on generating single cycle biphotons by noncollinear spontaneous parametric down-conversion (SPDC) in chirped quasi-phase-matching (QPM) periodically poled lithium niobate (PPLN) crystal have been studied in this paper. Numerical simulation shows that characteristics of the biphotons are mainly determined by the phase matching function which is dependent on the angle of the noncollinear SPDC and the temperature of the nonlinear crystal. Moreover, the angle plays a more significant role in noncollinear SPDC. The smaller angle and lower temperature can produce better phase matching effect while the angle and temperature changes within an appropriate range. The count rate of the biphotons will decrease, the bandwidth of biphotons will be compressed and the temporal width is widened for a certain appropriate angle in noncollinear SPDC while temperature is increased. However, as long as the angle and temperature are suitable, the biphotons generated by SPDC in the chirped QPM PPLN crystal are ultrashort pulses with single cycles.
We analysis the noncollinear Spontaneous Parametric Down Conversion (SPDC) and compare the biphotons generated by the chirped Quasi-Phase-Matching (QPM) between the Periodically Poled Lithium Niobate (PPLN) and Periodically Poled KTiOPO4 (PPKTP) crystals. Due to the chirping of the crystals, the frequency response range of the biphotons would be greatly increased. For nonlinear SPDC, angular variation is limited (less than 0.06° in this paper), and the angle would narrow the frequency response range of the biphotons. We compare the effect of angle in PPLN crystals and PPKTP crystals for biphotons. Both the two crystals with chirped QPM, the single-cycle biphotons can be generated during noncollinear SPDC within a suitable angle range, which is favorable for wider applications in experiments.