Three-dimensional imaging device and method based on optical frequency comb interferometry

Abstract

The invention belongs to the technical field of material morphology characterization, and particularly relates to a device and a method capable of performing three-dimensional imaging on a solid material. The device comprises a light source system, a light splitting element, a two-dimensional translation stage, a first reflector, a spectrograph and a signal processing system, the light source system comprises a femtosecond fiber laser, and the repetition frequency and the offset frequency of the femtosecond fiber laser are locked to an atomic clock to form an optical frequency comb; after a light beam emitted by the light source system is divided into two beams by the light splitting element, one beam is used as a reference light beam and vertically enters the first reflector; one beam isused as a detection light beam to be incident to the surface of a to-be-detected sample placed on the two-dimensional platform; the reference light beam and the detection light beam are respectively reflected and then returned to the light splitting element, the reference light beam and the detection light beam coincide at the light splitting element and interfere, and interference signals enter the spectrograph and then are calculated by the signal processing system to obtain the three-dimensional morphology of the to-be-detected sample. The three-dimensional morphology imaging of the sampleto be detected is realized, the measurement precision is high, and the device can be widely applied to the field of materials.

Description

technical field [0001] The invention belongs to the technical field of material morphology characterization, and in particular relates to a device and method capable of performing three-dimensional imaging on solid materials. Background technique [0002] Optical frequency combs appear as optical frequency sequences with equal frequency intervals in the frequency domain, and as electromagnetic field oscillation envelopes with femtosecond time width in the time domain. The time width satisfies the Fourier transform relationship. The distribution characteristics of ultrashort pulses in the time domain and frequency domain are similar to the combs we use every day. They are visually called frequency combs in the optical band, or "optical combs" for short. The optical comb is equivalent to an optical frequency synthesis generator. It is the most effective tool for absolute optical frequency measurement so far. It can accurately and simply link the atomic microwave frequency stan...

AI Technical Summary

Problems solved by technology

Photogrammetry is the earliest material characterization method proposed. This method can capture the measured sample in a wide range and properly process the sample photos. However, in order to realize the three-dimensional imaging of the sample, two or more cameras are needed. Not only complicate the measurement system, but also the measurement accuracy is relatively low

Coordinate measuring machines can also be used to image the target sample surface with high precision after continuously scanning the sample, however, the probe of the CMM needs to move across the sample surface, which may damage the sample

Images