共查询到20条相似文献,搜索用时 15 毫秒
1.
Kamada H Asobe M Honjo T Takesue H Tokura Y Nishida Y Tadanaga O Miyazawa H 《Optics letters》2008,33(7):639-641
We demonstrate 1500 nm band single-photon detection with low dark-count noise and a potentially high efficiency, which may allow long distance and high-bit-rate quantum key distribution. By developing frequency upconversion devices based on periodically poled lithium niobate waveguides, which are specifically designed to use a pump wavelength longer than that of communication-band photons, we completely eliminate the dark-count noise caused by parasitic nonlinear processes in the waveguide. We observed an internal conversion efficiency as high as 40% and demonstrated scaling down to the single photon level while maintaining a background dark-count rate of 10(2)s(-1). 相似文献
2.
We present a device to facilitate single-photon detection at communication wavelengths based on continuous-wave sum-frequency generation with an upconversion efficiency exceeding 90%. Sum-frequency generation in a periodically poled lithium niobate waveguide is used to upconvert signal photons to the near infrared, where detection can be performed efficiently by use of silicon avalanche photodiodes. 相似文献
3.
Combining reverse proton exchange and uniform periodic poling in LiNbO3 planar waveguides, we demonstrate low-energy spatial optical solitons by second-harmonic generation at room temperature, with a threshold as low as 23 pJ/microm at 1.5 microm. 相似文献
4.
E. Cantelar R.E. Di Paolo J.A. Sanz-García P.L. Pernas R. Nevado G. Lifante F. Cussó 《Applied physics. B, Lasers and optics》2001,73(5-6):515-517
In this work second-harmonic generation by quasi-phase matching (QPM) in Zn-diffused periodically poled lithium niobate channel
waveguides is presented. A stable TM?TE conversion by QPM has been found. The results are in good accordance with theoretical
estimations obtained by the phase-matching condition, either for the polarisation character of the second-harmonic wave as
well as for the spectral range, taking into account the periodicity of the domains.
Received: 16 May 2001 / Revised version: 7 September 2001 / Published online: 30 October 2001 相似文献
5.
In our experiment, two channels of a 3 cm long periodically poled lithium niobate (PPLN) waveguide are used to generate the nondegenerate spontaneous parametric down conversion (NSPDC) photon pairs. We experimentally obtained the highly efficient polarization-entangled photon pairs by coherently combining two NSPDC processes, and keeping the phase stable over 30 min. We can also prepare two entangled photon pairs with different central wavelengths with the help of wavelength division multiplex. 相似文献
6.
F. M. Pigozzo E. Autizi A. -D. Capobianco N. Argiolas M. Bazzan C. Sada 《Optical and Quantum Electronics》2006,38(9-11):889-901
We present a feasiblity study of a new method for enhancing the continuously phase matched second harmonic generation in 2D PPLN optical waveguides fabricated using the off-center Czochralski technique and proton-exchange. We show that a periodic variation of the nonlinear coefficient along the transverse coordinate permits for efficient energetic exchanges. 相似文献
7.
Quasi-phase-matched difference-frequency generation in periodically poled Ti:LiNbO(3) channel waveguides 总被引:1,自引:0,他引:1
Hofmann D Schreiber G Haase C Herrmann H Grundkötter W Ricken R Sohler W 《Optics letters》1999,24(13):896-898
Mid-infrared radiation near 2.8 mum was generated by difference-frequency generation in an 80-mm-long periodically poled Ti:LiNbO(3) channel waveguide by pump radiation near 1.55 mum (tunable external-cavity laser) and a signal radiation of 3.391 mum (HeNe laser). We obtained a normalized conversion efficiency of 105% W(-1) , which is to our knowledge the highest value ever reported. 相似文献
8.
Second harmonic generation in periodically poled LiNbO3 waveguides formed by oxygen‐ion implantation
Planar and channel waveguides were fabricatied in periodically poled lithium niobate crystals by 6 MeV O‐ion implantation. Single‐pass second harmonic generation was carried out. A conversion efficiency of 34.5%/(W · cm2) was achieved in the channel waveguide, and 1.11 mW second harmonic light at 492.5 nm was generated. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
9.
Bingxia Wang Shan Liu Tianxiang Xu Ruwei Zhao Peixiang Lu Wieslaw Krolikowski Yan Sheng 《中国光学快报(英文版)》2021,(6):50-53
The nonlinear Talbot effect is a near-field nonlinear diffraction phenomenon in which the self-imaging of periodic objects is formed by the second harmonics of ... 相似文献
10.
Efficient three-wave mixing devices have numerous applications, including wavelength conversion, dispersion compensation, and all-optical switching. Second-harmonic generation (SHG) is a useful diagnostic for near-degenerate operation of these devices. With buried waveguides formed in periodically poled lithium niobate by annealed and reverse proton exchange, we demonstrate what is believed to be the highest normalized conversion efficiency (150%/W cm(2)) for SHG in the 1550-nm communications band reported to date. 相似文献
11.
12.
We report high-power efficient green light generation by frequency doubling from a periodically poled MgO doped LiNbO(3) ridge waveguide. The ridge waveguide is fabricated by the annealed proton-exchanging and precise diamond blade dicing techniques. The ridge structure exhibits a surface roughness of only 3.7 nm, and near-90° vertical sidewall. The total insertion loss of an 8.5 μm wide and 1.4 cm long uncoated waveguide is 3.0 dB under direct fiber coupling. 466 mW of continuous-wave green light with an optical-to-optical conversion efficiency of 69.7% is obtained. To the best of our knowledge, this is the highest green light output power reached to date using a ridge-type LiNbO(3) waveguide device. Phase-matching temperature shift, tuning curve distortion, and waveguide loss increase are observed under high power operation. Our analysis shows that the photorefractive effect and the green induced infrared absorption are responsible for the observed phenomena, which becomes prominent under several megawatt per square centimeter power density. 相似文献
13.
An electro-optic tunable rectangular array illuminator in one-dimensional periodically poled LiNbO3 (PPLN) crystal is presented experimentally which result is in good agreement with results from simulation. The illuminator is formed based on the Talbot self-imaging effect by applying an electric field on PPLN. The intensity distribution of rectangular array could be precisely modulated. Compared with other array illuminators, this tunable illuminator uses a lower voltage and could get a more concentrated intensity distribution. The influence of the incident angle to the self-imaging patterns is studied for the first time. 相似文献
14.
G. Schreiber H. Suche Y.L. Lee W. Grundkötter V. Quiring R. Ricken W. Sohler 《Applied physics. B, Lasers and optics》2001,73(5-6):501-504
Using an FM-mode-locked Ti:Er:LiNbO3 waveguide laser as the fundamental source, wavelength conversion by cascaded χ(2):χ(2)-difference frequency generation with a conversion efficiency of up to +3(-4.6) dB was demonstrated at a pulse repetition
rate of about 2 (10) GHz. In addition, multi-channel conversion was demonstrated with a fully packaged wavelength converter
using a continuous fundamental source.
Received: 29 May 2001 / Revised version: 10 August 2001 / Published online: 2 November 2001 相似文献
15.
We retrieve intensity and phase profiles of 280 fs, 50 MHz optical pulses with 124 aJ coupled pulse energy (960 photons) by second-harmonic generation (SHG) frequency-resolved optical gating, using aperiodically poled LiNbO3 waveguides. The strong nonlinear interaction that is due to confinement within the micrometer-sized waveguide structure and the linearly chirped poling period contribute, respectively, to high SHG efficiency and broad phase-matching bandwidth. The achieved sensitivity is 2.7 x 10(-6) mW2, improving on the previous record for self-referenced complete pulse characterization by 5 orders of magnitude. 相似文献
16.
We experimentally demonstrate backward second-harmonic generation in periodically poled LiNbO(3) with a 3.3- microm domain period. We observed higher-order phase matching near 1490, 1600, and 1700 nm (fundamental) for the 19th, 18th, and 17th orders, respectively, with a maximum conversion efficiency of 0.02%. 相似文献
17.
We report the generation of 450-mW average blue (473-nm) power by frequency doubling of a diode-pumped 946-nm Nd:YAG laser. We achieved pulsed operation at a high repetition rate (~160kHz) by driving the relaxation oscillations of the laser. A 40% conversion efficiency to the second harmonic was obtained in a single-pass, extracavity, first-order, quasi-phase-matched process in which periodically poled lithium niobate (period 4.5microm , thickness 0.5mm , and length 15mm) at 140 degrees C was used. The resulting high-power blue beam was circular in profile and nearly diffraction limited, indicating that photorefractive effects do not appear to limit device performance. 相似文献
18.
Efficient cw 532?nm green-light generation is demonstrated using a periodically poled MgO:LiNbO3 ridge waveguide prepared by a process that combines annealed proton exchange and precise dicing. Performance of waveguides with different widths has been investigated. The 6-μm-wide, 1.6-cm-long uncoated ridge waveguide has achieved a green output power of 127?mW under a coupled fundamental light power of 250?mW. The highest conversion efficiency achieved is 53%. 相似文献
19.
Fiber-laser-based femtosecond parametric generator in bulk periodically poled LiNbO(3) 总被引:1,自引:0,他引:1
A diode-pumped system for optical parametric generation of wavelength-tunable femtosecond pulses is demonstrated. It comprises an Er-doped fiber mode-locked laser, a fiber chirped-pulse amplifier, and a bulk periodically poled LiNbO(3) (PPLN) optical parametric generator. The parametric generator is pumped at 777 nm with frequency-doubled microjoule pulses from the fiber amplifier and produces 300-fs pulses tunable from 1 to 3microm with output energies up to ~200 nJ. Use of a PPLN nonlinear crystal substantially reduces the pump energies required for efficient parametric generation. Saturated single-pass parametric energy conversion of 38% (internal) has been achieved with only 220 nJ of pump inside the crystal. A parametric generation threshold of 54 nJ is observed, and efficient parametric conversion is obtained with repetition rates up to 200 kHz. 相似文献
20.
An optical parametric generator based on periodically poled LiNbO(3) and pumped by a 2.051-mum-wavelength laser has been demonstrated. Pump pulses of 50-ns duration of 50-Hz repetition frequency were converted into signal and idler pulses in the 3.4-5.2-mum wavelength range in a double-pass pump configuration by a 5-cm-long quasi-phase-matched crystal. An average pump power of 180 mW generated 30-mW average signal power at 3.64-mum wavelength, corresponding to 16.7% signal conversion efficiency. 相似文献