Fig. 1. Conceptual diagram of a blocked LG beam healing system using a FP cavity. The blocked OV beam travels hundreds of times (depending on the q factor of the resonator) in the cavity when resonating. As the beam propagates back and forth, the blocked parts of the beam are 're-brightened'.

Fig. 2. Illustration of the experimental setup. A linearly polarized beam from a He-Ne laser propagated through a half-wave plate (HWP) and an optical isolator before being spatially filtered. The filtered beam then traveled through a 50/50 beam splitter (BS₁), which provided a normal incidence beam onto the spatial light modulator and a reference Gaussian beam for generating the interference patterns. The OV beam was reflected from the first diffraction order of the SLM and mode-matched to the FP cavity using a thin lens with a focal length of 250 mm. A blocking-plate was then used to precisely control the blocking of the incident beam of the FP cavity. The transmitted light was monitored using either a CCD camera or a photodiode.

Fig. 3. CCD captured experimental results. The first row shows the intensity distribution of the beams incident on the FP cavity with different unblocking percentages from 100% to 10%. The second row shows the intensity distribution of the transmitted light from the FP cavity with the resonant cavity length of the LG₀¹ beams. The third row shows the interference patterns between the transmitted light and the reference Gaussian beam.

Fig. 4. The various intensities of the transmitted light as a function of the change in the length of the Fabry-Pérot cavity as detected via a photodiode. When the unblocking percentage of the incident beams decreased, the intensity of the LG₀¹ peaks decreased because of the energy reassignment to other peaks.

Fig. 5. The transmitted curve of a 50% blocked LG₀¹ beam obtained from the scanning FP cavity and the intensity distributions of each main peak.

Fig. 6. Experimental results for LG₀² beam. (a) The intensity distribution of the LG₀² beam incident on the FP cavity with unblocking percentages of 50%. (b) The intensity distribution of the transmitted light from the FP cavity with the resonant cavity length of the LG₀² beam. (c) The interference pattern between the transmitted light and the reference Gaussian beam.