Fibre coupled dual-mode waveguide interferometer with $λ$/130 fringe spacing

Variable Free Spectral Range Spherical Mirror Fabry-Perot Interferometer

A spherical Fabry-Perot interferometer with adjustable mirror spacing is used to produce interference fringes with frequency separation (c/2L)/N, N=2-15. The conditions for observation of these fringes are derived from the consideration of the eigenmodes of the cavity with high transverse indices.

Coherent combining of self-cleaned multimode beams

A low intensity light beam emerges from a graded-index, highly multimode optical fibre with a speckled shape, while at higher intensity the Kerr nonlinearity may induce a spontaneous spatial self-cleaning of the beam [1,2]. Here, we reveal that we can generate two self-cleaned beams with a mutual coherence large enough to produce a clear stable fringe pattern at the output of a nonlinear interferometer. The two beams are pumped by the same input laser, yet are self-cleaned into independent multimode fibres. We thus prove that the self-cleaning mechanism preserves the beams' mutual coherence vi…

光学干涉仪中混合干涉条纹的解纠缠：理论与应用

Disentanglement of mixed interference fringes in optical interferometers: theory and applications

本文提出一种无需额外光学元件的条纹解纠缠理论，可将N孔径干涉图样数字化分解为N(N-1)/2条两两条纹，并通过仿真、实验及1.5米拼接镜定相验证其有效性。

Picometer-resolution dual-comb spectroscopy with a free-running fibre laser

Dual-comb spectroscopy utilizes two sets of comb lines with slightly different comb-tooth-spacings, and optical spectral information is acquired by measuring the radio-frequency beat notes between the sets of comb lines. It holds the promise as a real-time, high-resolution analytical spectroscopy tool for a range of applications. However, the stringent requirement on the coherence between comb lines from two separate lasers and the sophisticated control system to achieve that have confined the technology to the top metrology laboratories. By replacing control electronics with an all-optical du…

Revivals and oscillations of the momentum of light in a planar multimode waveguide

The evolution of the transverse momentum of monochromatic light entering a multimode planar waveguide at large angle is investigated. We report on oscillations of the momentum caused by the beatings between the adjacent populated modes of the waveguide and their periodic collapses and revivals. A new type of an interferometer based on this effect with fringe spacing as small as 1/9 of a light wavelength is demonstrated experimentally and periods as small as 1/1000 of a light wavelength seem to be feasible.

使用硅光子波导光栅耦合器的光波前相位倾斜测量

Optical wavefront phase-tilt measurement using Si-photonic waveguide grating couplers

本文提出两种基于硅光子波导光栅耦合器的波前相位倾斜传感器，分别利用光栅角度依赖性和干涉电路实现高灵敏度波前监测，无需体光学元件，可扩展用于自适应光学系统。