Device and method for rotatably controlling optical tweezers by femtosecond laser

Abstract

The invention provides a device and a method for rotatably controlling optical tweezers by femtosecond laser, and relates to the technical field of optically controlled optical tweezers. By the device and the method, a controlled object can be controlled rotatably in a high-precision, non-contact and scatheless manner. Seed light outputted by a femtosecond laser device passes through a diaphragm, an attenuation slice, total reflection planar mirrors and a vortex grating and then is divided into first-level diffraction light and a zero-level light beam; the first-level diffraction light and the zero-level light beam are reflected via the two total reflection planar mirrors and are coaxially superposed through a beam splitter so as to obtain a light beam with vortex information; the light beam is reflected into a microscope via a reflector so that an optical axis of the light beam is completely superposed to an optical axis of an imaging optical path of the microscope; in the microscope, a femtosecond pulse rotary arm and an imaging optical path of the microscope transmit light reversely, the light is focused via a high power objective lens so as to be converged into a light spot of which the radius is smaller than 1 micrometer, an optical potential well is formed, and objective particles move into the optical potential well and are captured stably and controlled rotatably. The device and the method are suitable for stably capturing grains and cells and rotatably controlling the grains and the cells.

Description

technical field [0001] The invention relates to the technical field of optical manipulation of optical tweezers. Background technique [0002] Since the emergence of optical tweezers technology, optical tweezers have been widely used in life sciences, medicine, physics, materials and nanoscience due to their non-contact and non-destructive manipulation of micro-nano-scale particles, and are considered to be the most ideal single molecule , single cell, particle, micro-nano device manipulation technology. [0003] Optical tweezers mostly use continuous laser and long pulse laser. Compared with continuous laser and long pulse laser, femtosecond laser pulse has extremely short pulse width, high peak power and time and space resolution, and can accurately detect Control action energy. In 2001, Tianjin University proposed the concept of femtosecond laser optical tweezers. Compared with continuous optical tweezers, the optical gradient force acting on particles in femtosecond op...

AI Technical Summary

Problems solved by technology

Gaussian beam is a traditional light source of optical tweezers. The best working area of ​​the optical trap formed by Gaussian beam focusing is near the beam focus. In recent years, many scholars have been exploring the use of various laser light sources and designing different optical paths to realize Optical manipulation of various particles and cells, but most technologies are limited to the capture and directional movement of particles, which limits the scope of application; at the same time, the traditional optical tweezers technology improves the capture force of optical tweezers by increasing the incident laser power, Increased capture force causes irreversible thermal damage to the sample

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