Nanjing University

University of Colorado

Academia Sinica

Shining Zhu

Ping Xu

Chao Zhang

Shuwei Huang

Andrew H Kung

Shih-Yu Tu

Zhenda Xie

Naiben Ming

Huitian Wang

Hua Jin

Zhida Gao

Yiqiang Qin

Jingliang He

Kunpeng Jia

Guozheng Ruo

Gang Zhao

Yongyuan Zhu

Xiaohan Wang

The present disclosure discloses a method and apparatus for generating an optical frequency comb. The specific generation method comprises: receiving a pump laser that matches a thermally stable state of a nonlinear optical resonant cavity and causing the pump laser to oscillate in the nonlinear optical resonant cavity, such that a Brillouin gain corresponding to the pump laser coincides with a target longitudinal mode in the nonlinear optical resonant cavity; continuously generating a Brillouin laser at the target longitudinal mode in the case that a pump power of the pump laser exceeds a threshold for generating the Brillouin laser; and generating an optical frequency comb by using the Brillouin laser through a Kerr nonlinear four-wave mixing process. According to the technical solution of the present disclosure, the nonlinear optical resonant cavity with the Brillouin gain can generate an optical frequency comb in its thermally stable region. This optical frequency comb not only has good stability, but also has low quantum noise and narrow linewidth characteristics.

Method and apparatus for generating optical frequency comb

A photonic chip based on periodical poling and waveguides circuits in ferroelectric crystals, the method is based on the integration of waveguide circuits, periodical poling and electro-optic modulator (EOM). The chip is illustrated by FIG.. The waveguide circuits guide the photons and makes linear operations like the beam splitting, filtering etc. on the photons. The periodical poling enables the efficient spontaneous parametric down conversion (SPDC), resulting the generation of entangled photons. The EOM controls the phase of photons dynamically. The following directional coupler distributes the entangled photons and the quantum interference takes place, resulting different types of path-entangled states by controlling the voltage of EOM insides the chip.

On-chip path-entangled photonic sources based on periodical poling and waveguide circuits in ferroelectric crystals

A tunable coherent light source includes a pump laser for generating a pump beam and an optical parametric oscillator including a crystal exhibiting an output curve for a pump beam of a defined wavelength, the output curve defining wavelengths of signal and idler outputs based on periodically poled grating periods of the crystal. The crystal has a plurality of segments associated with a plurality of grating periods of the output curve, each segment of the plurality of segments having a different crystal structure. At least one of the plurality of segments comprises a crystal structure combining at least two of the grating periods A heating device heats the crystal to an elevated operating temperature and is adjustable for adjusting the output wavelengths of each of the segments.

High repetition rate visible optical parametric oscillator

The design of a special type of optical superlattice and its application in the all-solid state laser is involved in this invention. Nd ions doped laser crystal in common use can radiate three relatively intense spectral lines when excited: the first wavelength is around 900 nm; the second wavelength is around 1064 nm; the third wavelength is around 1300 nm, whose accurate wavelength are depended on their host crystal (for example, to Nd:YAG, they are 946 nm, 1064 nm and 1319 nm, respectively). On the other hand, for LiNbO (LN), LiTaO (LT), KTP and other ferroelectric crystals, the positive and negative 180&deg; ferroelectric domains in these crystals can be arranged orderly according to certain sequence via crystal growth, electric field poling, and other state-of-the-art domain reversion technique, forming superlattice that is applicable to quasi-phase-matching (QPM) laser frequency conversion. This invention aims at the design of optical superlattice that can realize third-harmonic generation and coupled parametric process for such three emitting lines of Nd doped crystals and its application in the all-solid state laser. Such a superlattice, which can provide two or more effective reciprocal vectors, can participate in two or more QPM optical parametric processes. Different optical parametric processes in this kind of superlattice can couple each other via cascade effect. Therefore this type of superlattice can be used as an especial frequency-conversion crystal to acquire high-order harmonic generation of laser; in addition, it can realize the simultaneous output of multicolor laser or make the output of laser tunable by quasi-phase-matched frequency down-conversion. For instance, it is applicable to the frequency-conversion devices of all-solid state blue or ultraviolet laser, red-blue or green-ultraviolet dual color laser, and red-green-blue three fundamental colors laser, and can also be used as the source of entangled photon pair in the quantum telecommunication. The scheme can be extended to other active ions (such as Er, Yb, Tm, Sm etc.) doped laser crystal comprised in an all solid-state laser system.

Design of optical superlattice to realize third-harmonic generation and multi-wavelength laser output and its application in the all-solid state laser

Growing community of inventors

Nanjing, China

Shining Zhu