Characterizing Laser Beam Intensity Profile Using Fiber Optics Technique

Abstract

The low‑cost beam‑profiling approach that replaces a conventional pinhole scan with a cleaved optical fiber (quoted core ≈ 9 μm) mounted on an XY–Z translation stage is introduced in this study. The fiber tip is moved across the beam, with lateral step size of (125 µm), to obtain transverse intensity profiles for a He‑Ne (632.8 nm) and a green diode laser (532 nm); measurements at multiple axial positions (z = 0.5–3 m) and geometric formulas are used to estimate the 1/e² radius w(z), far‑field divergence, and the beam‑quality factor M² of the laser beam. Using this technique, the smooth normal distribution appears due to the relatively small size of the fiber optic core.