Abstract
We present a real-time complex amplitude reconstruction method for determining the beam propagation ratio M2 of laser beams based on the transport of intensity equation (TIE). In this work, a synchronous acquisition system consisting of two identical CCDs is established. Once two beam intensity images at different cross-section positions along the optical axis are captured simultaneously by the system, the complex amplitude of the laser beam can be rapidly reconstructed using TIE algorithm. Then the beam intensity distribution at any section position along its propagation direction can be obtained by using angular spectrum (AS) theory. The beam quality M2 factor is therefore calculated utilizing the second-order moments and hyperbola fitting methods, which conform to the ISO standard. The suitability of this method is verified by the numerical analysis and experiments with the He-Ne and high-power fiber laser sources, respectively. The experimental technique is simple and fast, which allows to investigate laser beams under conditions inaccessible to other methods.
Highlights
In laser applications, it is important to know the laser beam’s propagation characteristics as they directly influence the application quality [1,2]
We present a method for real-time complex amplitude reconstruction and dynamic beam quality M2 factor measurement on basis of the transport of intensity equation (TIE) technique [23,24]
We evaluate the performance of the real-time characterization method for laser beam quality based on the TIE technique by software simulations and experiments
Summary
It is important to know the laser beam’s propagation characteristics as they directly influence the application quality [1,2]. Jorge et al [1] presented a scattered light imaging method (SLIM) for the characterization of arbitrary laser beam intensity profiles It is fast and simple and a real-time, single-shot method with high accuracy and high sensitivity. Du et al [22] developed a new approach for real-time determination of M2 factor by amplitude and phase reconstruction based on a Mach-Zehnder self-referencing interferometer wavefront sensor It is simple, fast, and operates without moving parts. We present a method for real-time complex amplitude reconstruction and dynamic beam quality M2 factor measurement on basis of the transport of intensity equation (TIE) technique [23,24]. When the M2>>1, there are some limitations for the M2 factor to evaluate the beam quality
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
