Collimation Homogenization Converters CHC25-532-4-FTC4

Overview

The CHC25-532-4-FTC4 is a collimation homogenization converter (CHC) that turns a collimated Gaussian beam into a flat-top spot of Ø4 mm while preserving collimation. It is a three-piece flat-plate assembly — a structured waveplate between two parallel linear polarizers — built from Liquid Crystal Polymer/N-BK7 Window Plate/Linear Polarizing Film and mounted in a standard SM1 lens tube (SM1-8A Housing). Linearly polarized light passing through the structured waveplate becomes vector-polarized; the rear polarizer then attenuates the beam locally in space, so the Gaussian profile is flattened rather than diffracted. Designed for 532 nm with a Ø4 mm incident spot (Single mode, M2<1.3), it offers a Ø15 mm clear aperture and a working distance of 1800 mm.

Applications

• Beam homogenization for imaging and illumination
• Long-working-distance flat-top laser processing
• Machine vision and structured illumination
• Laboratory beam shaping on SM1 optical rails

Construction & Performance

Because the flat-top profile is produced by spatial intensity attenuation rather than by a diffractive structure, the converter keeps its flat-top shape over long propagation distances — unlike a DOE homogenizer, whose flat top only forms near the design plane. Spot uniformity is >90 %(RMS) with an edge roll-off of 0.885 mm, transmittance is >50 % and the anti-reflection coating is Ravg<0.5 %@400-700 nm. Surface parallelism is <3 arcmin and the element tolerates ±5 ° of incidence angle and ±0.2 mm (±5% of input beam diameter) of lateral misalignment. Key specifications for this model:

• Component size: Ø25.4×3.0 mm
• Operating Wavelength: 532 nm
• Incident spot diameter: Ø4 mm
• Output beam diameter: Ø4 mm
• Clear Aperture: Ø15 mm
• Angle of incidence: ±5 °
• Component Material: Liquid Crystal Polymer/N-BK7 Window Plate/Linear Polarizing Film
• Incident beam quality: Single mode, M2<1.3
• Incident light eccentricity (XY displacement): ±0.2 mm (±5% of input beam diameter)
• Surface Quality (Scratch/Dig): 60/40
• Transmittance: >50 %
• R Coating: Ravg<0.5 %@400-700 nm
• Surface Parallelism: <3 arcmin
• Uniformity of outgoing light spot: >90 %(RMS)
• Housing Specifications: SM1-8A Housing
• Edge Roll-Off (13.5% to 90%): 0.885 mm
• Working distance: 1800 mm

Storage & Handling

The converter is polarization-sensitive: feed it linearly polarized light and keep the input beam within the specified diameter, beam quality and eccentricity, otherwise the flat-top profile degrades. Handle the assembly by its SM1 housing, avoid touching the polymer surfaces, and clean only with a blower or optical-grade solvent on lens tissue. Store it in its original container in a clean, dry place away from direct sunlight and elevated temperature.