Multi-Focal DOE LCMF25-1064-F5-3-15

Overview

The LCMF25-1064-F5-3-15 is a focus-shaping optical element that turns a single incident beam into 3 equally spaced focal points of uniform energy along the axial direction. It is designed on diffraction principles and offers high diffraction efficiency and uniformity, and is intended for use with objective lenses. Operating wavelength is 1064 nm, with a focal spacing of 15 μm and a clear aperture of Ø7.5 mm.

Key Features

• Multiple foci along the axis — 3 equally spaced focal points with uniform energy distribution.
• Diffractive design — high diffraction efficiency and uniformity; focal energy uniformity >95%.
• Liquid crystal polymer construction — Liquid Crystal Polymer/N-BK7 WindowPlate in a sandwich-style flat-plate structure.
• Radially varying fast axis — the fast-axis orientation of the liquid crystal molecules varies periodically along the radius, with λ/2 retardation.
• Matched to objective lenses — objective focal length 5 mm, magnification 40X, numerical aperture 0.75.
• Customisation available — parameters and specifications can be tailored on request.

Applications

• Laser deep cutting — multiple axially distributed foci enable deep cutting of materials.
• Transparent material processing — cutting transparent glass, sapphire and similar substrates.
• Improved cut quality — a smoother and more uniform cutting surface than conventional single-focus laser cutting.
• Objective-based multi-focal setups — used in conjunction with objective lenses to meet multi-focal requirements in general applications.

Construction & Performance

The element is built from an N-BK7 glass substrate and liquid crystal polymer (LCP): two 1-inch glass substrates enclose a single LCP layer carrying the designed phase, which makes it a single-wavelength device. Photo-alignment forms the phase structure in the LCP film, modulating the phase of the incident light so that it is dispersed into different diffraction orders and then focused by an objective lens into multiple foci.

• Component Size: Ø25.4x3.2 mm
• Operating Wavelength: 1064 nm
• Clear Aperture: Ø7.5 mm
• Focal Length: 15 μm
• Component Material: Liquid Crystal Polymer/N-BK7 WindowPlate
• Incident spot size (@1/e²): Ø7 mm
• Incident light polarization state: Circularly polarized light
• Center offset: <100 μm
• Retardance: λ/2
• Delay Accuracy & Uniformity: ±5 nm
• Focal Energy Uniformity: >95%
• AR Coating: 700-1100 nm
• Reflectivity: Ravg<0.5% (0° incidence)
• Transmittance (@working wavelength): >98%
• Number of Focus Points: 3
• Objective Focal Length: 5 mm
• Objective Magnification: 40X
• Objective Numerical Aperture: 0.75
• Surface Quality (Scratch/Dig): 60/40

Storage & Handling

Operate and store within the specified environmental limits. Handle the coated surfaces by the edges only and keep the clear aperture free of contamination; clean with optical-grade solvents and lint-free wipes when required.