Flat Lenses PBL25-532-F50

Overview

This Flat Lens is a planar diffractive optical element that focuses or diverges an incident beam according to its polarization state. The polarization of the transmitted light is reversed relative to the incident light, so by controlling the incident polarization the energy can be distributed between the converging and diverging focal spots. Operating as a planar diffractive device, its diffraction angle follows the relation sinθ = λ/p, and the continuously varying periodic structure yields an aberration-free response in which all rays converge to a common focus. This unit is designed for an operating wavelength of 532 nm with a focal length of 50.0 mm.

Applications

• Polarization-controlled beam focusing and defocusing
• Beam shaping and wavefront manipulation in laser systems
• Compact focusing and imaging modules where a thin planar element is preferred
• Polarization-sensitive optical setups, interferometry and metrology
• Spectroscopy and laser beam delivery at the design wavelength

Construction & Performance

The lens is built as a sandwich planar structure combining a liquid crystal polymer layer with an N-BK7 window substrate. The fast-axis orientation is continuously graded, with the radial alignment period decreasing toward the edge to form the diffractive phase profile. This single-wavelength, large-dispersion design is free of spherical aberration. Key specifications for this model:

• Operating Wavelength: 532 nm
• Focal Length: 50.0 mm
• Clear Aperture: Ø20.0 mm
• Optical Component Size: Ø25.4x3.2 mm
• Substrate Material: Liquid Crystal Polymer/N-BK7 Window Plate
• Diffraction Efficiency: >98%
• Surface Quality (Scratch/Dig): 60/40
• AR Coating Band: 400-700 nm
• AR Coating Reflectance: Ravg <0.5% (0° incidence)
• Transmittance (at working wavelength): >97% @532 nm
• Operating Temperature: -20 to 80 deg C

Storage & Handling

Handle the element by its edges and avoid contact with the clear aperture. Keep the optical surfaces free of dust and fingerprints; when cleaning is required, use clean optical-grade solvents and lens tissue. Store in the original container in a clean, dry environment within the rated operating temperature range, away from direct sunlight, condensation and corrosive vapors.