arXiv:1007.2995 · Optics Express

Generation of squeezed light with a monolithic optical parametric oscillator: Simultaneous achievement of phase matching and cavity resonance by temperature control

Hidehiro Yonezawa, Koyo Nagashima, Akira Furusawa

Published Sep 7, 2010• 27 citations

Abstract

We generate squeezed state of light at 860 nm with a monolithic optical parametric oscillator. The optical parametric oscillator consists of a periodically poled KTiOPO(4) crystal, both ends of which are spherically polished and mirror-coated. We achieve both phase matching and cavity resonance by controlling only the temperature of the crystal. We observe up to -8.0±0.2 dB of squeezing with the bandwidth of 142 MHz. Our technique makes it possible to drive many monolithic cavities simultaneously by a single laser. Hence our monolithic optical parametric oscillator is quite suitable to continuous-variable quantum information experiments where we need a large number of highly squeezed light beams.

DOI: 10.1364/oe.18.020143

Related papers

Design of optical parametric cavity for broadband squeezed light field

Junping Wang, Wenhui Zhang, Ruixin Li +3 more

The field of squeezed state is an important quantum resource in the study of quantum optics. In the application of quantum information, the spectrum bandwidth of the squeezed light field is an important index to limit the information transmission capacity. Currently, the optical parametric oscillator (OPO) is one of the most efficient ways to generate high squeezed non-classical optical fields. In this paper, the degenerate singly-resonant and doubly-resonant OPO structures are introduced. Both OPOs are composed of concave mirrors and periodically poled potassium titanyl phosphate crystals (PPKTP). The length of PPKTP crystal is 10 mm. The curvature radius of the curved surface is 12 mm, and it has high reflectivity at 1550 nm and 775 nm. The plane surface is coated with anti-reflection coating. The air gap length is 21 mm. The concave mirror is an output coupling mirror, and its radius of curvature is 25 mm. In the singly-resonant OPO, only the signal light resonates in the cavity, and the pump light passes through the nonlinear crystal twice and then outputs out of the cavity. The reflectivity of OPO output coupling mirror to the wavelength of 1550 nm is 88%. The linewidth of the corresponding fundamental frequency wave is 77.4 MHz. For doubly-resonant OPO, both the signal light and the pump light resonate simultaneously in the cavity. The reflectivity of OPO output coupling mirror to 1550 nm and 775 nm is 85% and 97.5%, respectively. The linewidth of the corresponding fundamental frequency wave and harmonic is 97.1 MHz and 15.6 MHz, respectively. Then the threshold of OPO is calculated. The threshold pump power of OPO increases with signal light transmittance increasing, but the threshold value of doubly-resonant OPO is obviously smaller than that of singly-resonant OPO. After that, the variation of the squeezing bandwidth of the squeezed light field generated by OPO with the transmittance of the signal is analyzed. Finally, we complete the design of quantum squeezer with low threshold (18 mW), broadband (84.2 MHz) and high stability (the standard deviation of locking baseline is 0.32 MHz) experimentally. The results show that compared with the singly-resonant optical parametric oscillator, the doubly-resonant cavity has the characteristics of low threshold and high stability, which is more suitable for the preparation and practical application of broadband squeezed light field.

Acta Physica SinicaJan 1, 20203 citations

Experimental study on mode matching for preparation of squeezed light at 1064 nm

Fei Feng, Tongyi Zhang, Wenyan Qu +1 more

The effect of mode matching on the preparation of the squeezed light at 1064 nm with periodically poled KTiOPO 4 (PPKTP) crystal is reported. We can derive the desired mode by improving the spatial mode matching into optical cavities, including the beam from the laser mode matched to the optical parametric amplifier cavity and mode cleaning cavity; also it is useful for the stability of the locking systems. By increasing the fringe visibility between the squeezed light and the local oscillator beam, a squeezing level of −8.75 dB or even higher could be observed, even with the same experimental parameters as described elsewhere.

Optical EngineeringAug 1, 20134 citations

Generation of two types of nonclassical optical states using an optical parametric oscillator with a PPKTP crystal

Meiru Huo, Jiliang Qin, Zhihui Yan +2 more

As important members of nonclassical states of light, squeezed states and entangled states are basic resources for realizing quantum measurements and constructing quantum information networks. We experimentally demonstrate that the two types of nonclassical optical states can be generated from an optical parametric oscillator (OPO) involving a periodically poled KTiOPO4 crystal with a domain-inversion period of 51.7 μm, by changing the polarization of the pump laser. When a vertically polarized 671 nm laser is used to pump the OPO, the intra-cavity frequency-down-conversion with type-0 quasi-phase matching is realized and the output optical beam is a quadrature amplitude squeezed state of light at the wavelength of 1342 nm with the fluctuation of quadrature component of 3.17 dB below the quantum noise limit (QNL). If the pump laser is horizontally polarized, the condition of the type-II quasi-phase matching is satisfied and the output optical beam becomes Einstein-Podolsky-Rosen entangled state of light with correlation variances of both quadrature amplitude-sum and quadrature phase-difference of 2.2 dB below the corresponding QNL.

Applied Physics LettersNov 28, 201616 citations

Generation of highly squeezed light at 860 nm

Kengo Nagashima, Genta Masada, Hajime Arao +3 more

We obtained -9.55plusmn0.03 dB squeezed vacuum at 860 nm by using a subthreshold optical parametric oscillator (OPO) with a periodically poled KTiOPO4(PPKTP) crystal as a nonlinear optical medium.

International Nano-Optoelectronics WorkshopAug 1, 20080 citations

Generation of Highly Squeezed Light at 860 nm

Genta Masada, Koyo Nagashima, Hajime Arao +4 more

We report generation of squeezed light at 860 nm by utilizing a subthreshold optical parametric oscillator with a periodically poled KTiOPO4 crystal as a nonlinear medium. At the pump power of 130 mW we observed the squeezing level of −9.55 dB and antisqueezing level of +16.36 dB.

AIP conference proceedingsJan 1, 20090 citations

Watt-level single-frequency optical parametric oscillator around 2 µm

Nicola Coluccelli, Giovanni Cichelli, M. Polastri +3 more

A single-frequency optical parametric oscillator (OPO) operating in the wavelength range around 2 µm is reported. The OPO comprises a periodically poled LiNbO 3 (PPLN) crystal for quasi-phase matching and a four-mirror ring-cavity resonant to the signal. The OPO signal and idler are tuned from 1.89 to 2.05 µm and from 2.21 to 2.42 µm, respectively, by changing the crystal temperature. Output powers in excess of 2 W are demonstrated at a pump power of 9 W for both the signal and idler over all of the respective tuning ranges. A detailed characterization of the intensity and frequency noise is presented. The OPO exhibits an integrated intensity noise below 0.1% and a linewidth of ∼58 kHz for an observation time of 1 ms. The reported performance makes this source an ideal candidate for the generation of squeezed light around 2 µm via cascaded second-harmonic generation (SHG) and parametric downconversion (PDC).

Optics LettersSep 20, 20245 citations