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1.
I. Rabbiosi A.J. Scroggie G.-L. Oppo 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(3):453-459
Quantum fluctuations of the signal field are shown to induce packed arrays of cavity solitons in a degenerate optical parametric
oscillator above threshold in the limit of large pump finesse relative to the signal finesse. The cavity solitons in the array
are formed by locked domain walls, and lead to a highly correlated quantum structure. The effect of the quantum fluctuations
is non-trivial since the arrays of cavity solitons have a far less stable than other stable solutions and disappear with decreasing
pump finesse. The transition from disorder to order due to quantum noise is also discussed.
Received 20 September 2002 / Received in final form 28 November 2002 Published online 11 February 2003 相似文献
2.
V. A. Averchenko Yu. M. Golubev C. Fabre N. Treps 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,61(1):207-214
We present a simple quantum theory for the pulsed light generated by a synchronously pumped optical parametric
oscillator (SPOPO) in the degenerate case where the signal and idler trains of pulses coincide, below threshold and
neglecting all dispersion effects. Our main goal is to precise in the obtained quantum effects, which ones are
identical to the c.w. case and which ones are specific to the SPOPO. We demonstrate in particular that the temporal
correlations have interesting peculiarities: the quantum fluctuations at different times within the same pulse turn
out to be totally not correlated, whereas they are correlated between nearby pulses at times that are placed in the
same position relative to the center of the pulses. The number of significantly correlated pulses is of the order of
cavity finesse. We show also that there is perfect squeezing at noise frequencies Wm\Omega_m = 2π
m/T
R
(m = 0, 1, 2,?\ldots where T
R
is the pulse train period) when one approaches the threshold from below on the signal
field quadrature measured by a balanced homodyne detection with a local oscillator of very short duration compared to
the SPOPO pulse length. 相似文献
3.
利用半经典理论方法计算了运转于阈值以上的非简并光学参量振荡腔输出信号场、闲置场及反射抽运场的关联特性. 根据 van Loock 等提出的连续变量多组分纠缠判据, 计算结果表明, 常温下这三个光场的正交振幅分量与正交位相分量之间存在三组分量子关联, 得到了三色三组分纠缠态光场. 数值计算了关联噪声对参量振荡腔物理参数的依赖关系, 找出了产生三色三组分纠缠态产生的最佳运转条件, 为连续变量多组分纠缠态光场产生系统的设计提供了直接参考.
关键词:
连续变量
非简并光学参量振荡腔
三色三组分纠缠态 相似文献
4.
Three-colour continuous-variable (CV) entanglement can be directly generated by an injection-seeded nondegenerate optical parametric oscillator (INOPO). The quantum correlations among the pump, signal, and idler beams are calculated and discussed by applying sufficient inseparability criteria for CV entanglement. The results clearly show that strong three-colour CV entanglement can be produced by operating the pump above the oscillation threshold. The INOPO is easier to realize experimentally and more steady in comparison to that without an injected signal since the injected signal can increase the nonlinear conversion efficiency and the stability, as well as allow a large degree of tunability. This scheme can be very useful for the applications in quantum communication and computation networks. 相似文献
5.
6.
Quantum correlations among bright pump, signal, and idler beams produced by an optical parametric oscillator, all with different frequencies, are experimentally demonstrated. We show that the degree of entanglement between signal and idler fields is improved by using information on pump fluctuations. To our knowledge this is the first observation of three-color optical quantum correlations. 相似文献
7.
V. A. Averchenko T. Yu. Golubeva Yu. M. Golubev C. Fabre 《Optics and Spectroscopy》2008,105(5):758-770
Information applications of the essentially multimode (in time) radiation of a degenerate optical parametric oscillator operating above the oscillation threshold, such as protocols of quantum parallel dense coding and multimode quantum teleportation, have been considered. The stream of Shannon mutual information as a function of the spectral width of Alice’s signal and the spectral fidelity of transmission of a multimode quantum signal are evaluated from the estimates of the achievable radiation squeezing that occurs as the oscillation threshold is approached. The advantages of the multimode scheme over the single-mode scheme are discussed. 相似文献
8.
The generation of pulsed squeezed light using an optical parametric oscillator (OPO) is discussed. This mode-locked optical parametric oscillator consists of a nonlinear crystal in a cavity which is resonant for both signal and idler waves and which is synchronously pumped by the second-harmonic of an acousto-optically mode-locked cw Nd: YAG laser. The fundamental wavelength of the pump laser provides local oscillator pulses for balanced homodyne detection of squeezed vacuum pulses emitted by the oscillator when operated below oscillation threshold. Photocurrent noise reduction to 30% below the classical shot-noise limit is observed, corresponding to squeezing of the field to a level approximately a factor of two below the mean square vacuum noise. 相似文献
9.
对基于周期极化掺镬铌酸锂晶体的信号光单谐振光学参量振荡器的输出特性进行了实验研究.讨论了光学参量振荡器谐振腔的腔长、周期极化铌酸锂晶体的通光长度、输出镜的透过率以及抽运光的脉冲宽度对光学参量振荡器谐振阈值的影响.光学参量振荡器的抽运源采用输出波长为1 064 nm的声光调Q Nd:YVO_4激光器,在重复频率为2 kHz、周期极化掺镁铌酸锂晶体的温度为30℃的条件下,光学参量振荡器的振荡阈值仅为48 mW.当抽运功率为94 mW时获得了25 mW的信号光输出,其光-光转换效率为26.6%. 相似文献
10.
对基于周期极化掺镁铌酸锂晶体的信号光单谐振光学参量振荡器的输出特性进行了实验研究.讨论了光学参量振荡器谐振腔的腔长、周期极化铌酸锂晶体的通光长度、输出镜的透过率以及抽运光的脉冲宽度对光学参量振荡器谐振阈值的影响.光学参量振荡器的抽运源采用输出波长为1 064 nm的声光调Q Nd∶YVO4激光器,在重复频率为2 kHz、周期极化掺镁铌酸锂晶体的温度为30 ℃的条件下,光学参量振荡器的振荡阈值仅为48 mW.当抽运功率为94 mW时获得了25 mW的信号光输出,其光-光转换效率为26.6%. 相似文献
11.
Our treatment is based on a microscopically correct Hamiltonian which contains the Bose-operators of the light modes and the Fermi-operators of the optically active electrons in the medium. The coupling between modes and atoms is taken from quantum-electrodynamics. Besides that, the light modes may interact with external “heat baths” like the mirrors, scattering centers etc., while the atoms interact with lattice vibrations, incoherent light fields etc. Using recently developed methods the effect of these heatbaths is taken into account in a quantum mechanically consistent fashion. In the present paper we apply quantum mechanical Langevin equations for the field and electron operators which contain dissipation and fluctuation terms. The elimination of the electron operators by an iteration procedure finally leaves us with a set of coupled nonlinear field equations which are shown to be quantum mechanically consistent. They are solved in the Heisenberg picture below threshold by linearization and well above threshold by quantum mechanical quasi-linearization. The solutions show that the line width of the signal mode below threshold is due to the vacuum fluctuations in the idler and vice versa, whereas the thermal noise of the resonator and the spontaneous emission noise of the medium may be neglected. Above threshold the linewidth is caused by the undamped diffusion of the phase difference between signal and idler, to which the vacuum fluctuations of both modes contribute in equal parts. The phase sum of both modes adiabatically follows the slow phase diffusion of the external pump light, produced by a laser, and therefore contributes to the linewidth too. Well above threshold the amplitudes are stable. Correlation and cross-correlation functions of their small residual fluctuations are calculated. 相似文献
12.
We calculate the quantum correlations existing among the three output fields (pump, signal, and idler) of a triply resonant nondegenerate optical parametric oscillator operating above threshold. By applying the standard criteria [P. van Loock and A. Furusawa, Phys. Rev. A 67, 052315 (2003)], we show that strong tripartite continuous-variable entanglement is present in this well-known and simple system. Furthermore, since the entanglement is generated directly from a nonlinear process, the three entangled fields can have very different frequencies, opening the way for multicolored quantum information networks. 相似文献
13.
Synchronously pumped Raman oscillators allow for an efficient frequency conversion of pump pulses whose power is well below the threshold for extracavity stimulated Raman scattering (SRS). Numerical simulations show that the cavity mismatch of pump laser and Raman oscillator is critical for maximum conversion efficiency and minimum pulse duration for transient and stationary SRS. At a certain mismatch the simulations predict a quasi-cw Raman oscillator output even at moderate cavity quality factors. Optimum operation conditions are discussed for pump pulse trains of finite lengths. The results of the numerical calculations are in qualitative agreement with a simple phenomenological model. PACS 42.55.Ye; 42.65.Dr; 42.55.Lt 相似文献
14.
Squeezing of the intracavity field in a degenerate parametric oscillator is calculated above threshold neglecting pump depletion. Arbitrary squeezing is in principle obtainable. We conclude that above threshold squeezing in the steady-state parametric oscillator is limited primarily by pump depletion rather than degradation by vacuum fluctuations at the mirrors. The squeezing predicted by the present calculation should be observable in an oscillator operated in a transient or pulsed mode 相似文献
15.
A fully conductively cooled and diode-pumped linear Ho:Tm:LuLiF laser oscillator can generate more than 1 J normal mode pulses at a 10 Hz pulse repetition rate where heat pipes are used for cooling pump diodes and laser crystal. As an amplifier, it can amplify the 80 mJ/180 ns pulses into 400 mJ pulses before the appearance of amplified spontaneous emission (ASE). The ASE threshold is about 5.6 J with a 40 mm long and side-polished laser crystal. For a 5 mJ input pulse and 5.6 J pump pulse, the double-pass gain exceeds 22.5. If the lateral surface of the laser crystal is fine ground, the ASE threshold can rise to higher than 8 J, but the efficiency will be lower due to large pump diffusion. 相似文献
16.
We have generated femtosecond subharmonic pulses by using an optical parametric oscillator. The optical frequencies of the idler and the signal are one third and two thirds, respectively, of the optical frequency of the pump pulse. The carrier phase of the signal pulse relative to that of the pump pulse was locked by electronic feedback. The carrier-envelope phase slip frequency of the signal pulse relative to that of the pump was locked to F/6 , where F is defined as the repetition frequency. 相似文献
17.
The excess fluctuations of the phase-conjugate (PC) signal generated via pulsed degenerate four-wave mixing (DFWM) in sodium vapor are investigated. Various dye-laser oscillator and amplifier combinations are employed to trace the sources of these fluctuations. For DFWM driven by an externally-stabilized cw dye-laser oscillator amplified with a dye system pumped by the smoothed pulses of a Nd:YAG laser, the PC excess fluctuations are very highly correlated with the energy fluctuations of the input amplified dye-laser pulses. Thus, input-pulse selection on the basis of energy alone permits observation of the quantum-mechanical fluctuations of the PC signal. 相似文献
18.
M. Hoyuelos G.-L. Oppo P. Colet M. San Miguel 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,22(3):441-451
We analyze the quantum fluctuations of the degenerate optical parametric oscillator close to an instability for the formation
of a square pattern. While strong correlations between the fluctuations of the signal modes emitted at the critical wave number
and with opposite wave vector are present both below and above threshold, no features signaling the square character of the
pattern forming above threshold have been identified below threshold in the spatio-temporal second-order coherence. We also
explore in which regimes a reduced few mode model gives meaningful results.
Received 17 September 2002 / Received in final form 11 November 2002 Published online 26 February 2003 相似文献
19.
Synchronized signal (650 ps) and pump (1.3 ns) pulses were generated using 4-pass geometry in a grating pair based pulse stretcher
unit. The pump pulse has been further amplified in a high gain regenerative amplifier. This amplified pulse was used as the
pump in an optical parametric chirped pulse amplification based Nd:glass laser system. As the chirped signal pulse and the
pump pulse originated from the same oscillator, the time jitter between the pump pulse and the signal pulse can be <50 ps. 相似文献
20.
We report extended mode-hop-free tuning in a continuous-wave, pump-enhanced optical parametric oscillator (PE-OPO). We employ a dual-cavity configuration to allow independent control of the resonant pump and signal fields, and so we can suppress frequent mode hops in the signal as the pump is tuned in frequency. With the signal field clamped in frequency by an uncoated etalon, the idler field can be scanned smoothly through a range of 10.8 GHz. The PE-OPO outputs can also be tuned coarsely from 1.01 to 1.18 mum in the signal and from 2.71 to 3.26 mum and 4.07 to 5.26 mum in the idler. We find that increased idler absorption only slightly increases the oscillation threshold. 相似文献