Research

Slanted Hole Array Beam Profiler (SHArP) - A high-resolution portable beam profiler based on a linear aperture array

We developed a novel high-resolution portable beam profiler based on a slanted linear array of small apertures?termed slanted hole array beam profiler (SHArP). The apertures are directly fabricated on a metal coated CMOS imaging sensor. With a single linear scan, the aperture array can establish a virtual grid of sampling points for beam profiling. With our prototype, we demonstrate beam profiling of Gaussian beams over an area of 66.5 μm x 66.5 μm with a resolution of 0.8 μm (compare to the CMOS pixel size of 10 μm). The resolution can be improved into the range of submicron by fabricating smaller apertures. The good correspondence between the measured and calculated beam profiles proves the fidelity of our new beam profiling scheme.

Figure 1. (a) Principle of the SHArP (b) Topview and image reconstruction of the SHArP. (c) The PSF of the SHArP prototype measured by NSOM.

Figure 2. The focal beam profile of the Gaussian beam (a) measured by SHArP, (b) imaged by the CMOS imaging sensor. The focal beam profile of the Gaussian beam confined by an iris diaphragm in width (c) measured by SHArP, (d) imaged by the CMOS imaging sensor. The cross section of the focal beam profile of the Gaussian beam in X direction (e), and in Y direction (f). (Measured ‘o’, calculated ‘-’ ).

Figure 3. The focal diffraction pattern of the Gaussian beam confined by an iris diaphragm in width (a) measured by SHArP (b) calculated. (Zeroth order has been truncated).

References

Xiquan Cui, Xin Heng, Jigang Wu, Zahid Yaqoob, Axel Scherer, Demetri Psaltis, and Changhuei Yang. Slanted Hole Array Beam Profiler (SHArP) - A high resolution on-chip beam profiler based on a linear aperture array, Optics Letters, accepted (2006). (pdf)