Multi-channel Spatial Structure Light Field Generation Device Based on Improved Michelson Interferometer

Abstract

The invention discloses a multi-channel space structure light field generation device based on an improved michelson interferometer. The device is characterized in that a light source is led into a michelson interferometer system through plus and minus one level diffraction of a liquid crystal element, and two reflecting mirrors in the michelson interferometer are improved, wherein one reflecting mirror is replaced with a total reflection prism so that exchange of a plus diffraction level propagation light path and a minus diffraction level propagation light path can be achieved, and a spatial filter is placed in front of the total reflection prism to select the needed plus and minus one level diffraction; the other reflecting mirror is changed to only reflect one level of diffraction, and thus control over the phase and polarization can be completed in one light path, and the multi-channel space light field generation device is implemented. Meanwhile, according to a method for adjusting and having control over polarization through coherence stack, basic vector switching can be achieved easily, conveniently and fast by directly removing or adding a quarter wave plate or other phase optical elements such as spiral phase plate, and thus subsequently, the device can be applied to experiments with specific requirements for light source polarization and phases conveniently and widely.

Description

technical field [0001] The invention relates to a new technology for generating a spatial light field, and designs and implements a set of multi-channel spatial structure light field generating devices that can simultaneously regulate the polarization and phase of the light field. Background technique [0002] Different from traditional light fields, spatially structured light fields are light fields in which the amplitude, polarization, and phase have specific distributions in space. The particularity of its polarization and phase brings a series of novel optical properties, which can be applied to optical communication, light harvesting and optical manufacturing, etc. The generation technology and application research of spatially structured light fields have attracted extensive attention. [0003] The light field with a special polarization distribution in the spatially structured light field is called a vector light field, which is a special light field whose polarizatio...

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Problems solved by technology

Compared with the work of StefanBernet et al., this optical path makes full use of the resolution of the liquid crystal panel, but the disadvantage of this method is that due to the large period of the holographic grating, the spatial distance of ±1 level on the grating spectrum plane is very close, so among them The slit spacing as a filter element is very small, and two quarter-wave plates need to be placed behind the two slits and the angle of the wave plates should be adjusted, which is very difficult to operate

The last is to use the grating to recombine the regulated ±1st-order diffracted light, which requires the beam combining grating to match the hologram loaded by the SLM, which limits its flexibility

The Zhao Jianlin group of Northwestern Polytechnical University further improved its generation optical path, and proposed a vector light field generation system based on Sagnac interferometer (Generation of far bitrary spatially variant polarization beams with a trapezoid Sagnac interferometer, Optics Express, Vol.20, Issue 19, pp.21715-21721 (2012)): A polarizing beam splitting element directly splits the incident light into two mutually orthogonal polarized beams, which are then incident on the liquid crystal panel loaded with a holographic grating in advance to obtain the required helical phase, thus solving the problem of the control behind the slit in the previous method The quarter-wave plate of the beam polarization is not easy to adjust and the beam combination is difficult

However, due to the introduction of polarization beam splitting elements in the optical path, the adjustment difficulty is increased, especially when the optical path switches the base vector, it is more complicated

All the above-mentioned methods only control the polarization characteristics of the light field, and the phase control of the light field is also a very important part of the spatial light field control. It is very difficult to achieve separate control of the beam polarization and phase, and additional To build a phase-modulated optical path, we have invented a multi-channel spatially structured light field generation device based on an improved Michelson interferometer for the shortcomings of existing methods such as inconvenient switching of base vectors, poor stability of the optical path, and inability to achieve simultaneous adjustment of phase and polarization.

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