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Polarization Directed Lenses

Polarization Directed Lenses function differently than typical spherical lenses. The focal length is defined by a holographically recorded wavefront profile, rather than by the curvature of the surfaces. Thus, Polarization Directed Lenses have less weight and volume than comparable spherical lenses, making them ideal for space-constrained applications. Polarization Directed Lenses are the result of exciting new design technology, allowing for endless possibilities across various industry fields and application types.

Key Features

✔ Thin (0.45mm) and Flat for Weight or Space Sensitive Applications

✔ Negative or Positive Focal Length Based Upon the Input Polarization

✔ No Spherical Aberration

✔ Ultra-low Loss

✔ AR Coated for High Visible Light Transmission

✔ Negative Dispersion for Unique Chromatic Aberration Correction in Multi-Element Designs

RHCP - Right-Handed Circular Polarization

LHCP - Left-Handed Circular Polarization

Product and Technology Overview

An introduction to the science, technology, and fabrication of Polarization Directed Lenses.

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Technology Journal Article

Fabrication of ideal Geometric Phase (GP) holograms with arbitrary wavefonts.

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FAQ's

What is a Polarization Directed Lens?

A Polarization Directed Lens is a thin (0.45mm) flat window with a complex photo-aligned liquid crystal polymer (LCP) film deposited on the surface. By varying the geometrical phase shift spatially, the LCP achieves near perfect diffraction efficiency of the holographically recorded lens wavefront. Essentially, a Polarization Directed lens is a thin film equivalent of a geometric optic with very little volume, yielding significant reductions in weight and thickness.

How does Polarization affect the performance?

The Polarization Directed Lenses are sensitive to circular polarization. The lenses have the unique property that one circular polarization will focus or converge through the lens (positive focal length) and the orthogonal circular polarization will defocus or diverge (negative focal length).

When the lens is oriented with the LCP surface facing the light source: Left-Hand Circular Polarization (LHCP) light will focus with the stated positive focal length of the lens. Right-Hand Circular Polarization (RHCP) light will diverge with the negative stated focal length of the lens.
When the lens is oriented with the LCP surface away from the light source: RHCP light will focus with the stated positive focal length of the lens. LHCP light will diverge with the negative stated focal length of the lens.

Will the lens focus unpolarized light?

With unpolarized light, the Polarization Directed Lens will act as a positive lens for 50% of the light (one of the circular polarizations) and it will act as a negative lens for the other 50% of the light (the orthogonal polarization).

What happens with linear polarized light?

Linear polarized light will act the same as unpolarized – 50% of the light will be focused, and 50% of the light will be diverged with a negative focal length.

What are the advantages of Polarization Directed Lenses?

Polarization Directed Lenses are a thin film equivalent of a geometric optic. Thus, they have significantly less volume than an equivalent spherical optic, yielding significant reduction in weight and thickness. The technology used to create them is also well suited to create gratings and other polarization optics, allowing for multiple optical technologies to be designed into a single optical component.

Are there any disadvantages to Polarization Directed Lenses?

To operate as efficiently as possible, the lenses require the incoming light to be circularly polarized. This requires extra care in the setup, and potentially additional polarization optics in the optical design. Also, the lenses function as a grating, and thus have significant chromatic aberration when used with broadband illumination. Care should be taken to limit the spectral bandwidth of the illumination for optimum results.

How can I specify a custom Polarization Directed Lens?

To create a custom Polarization Directed Lens, the following information is required:

Lens Size (Diameter, Square, etc)
Clear Aperture
Maximum Thickness
Desired Focal Length
Operating Wavelength Range
Wavefront Characteristics (aspheric, etc)
AR Coating Specs (wavelength, reflectance, etc.)
Wavefront Accuracy

How should I clean my Polarization Directed Lens?

Polarization Directed Lenses can be cleaned with the same methods used for other anti-reflection coated optics. Visit our application note on Cleaning Optics for more information.

How can I mount my Polarization Directed Lens?

All of our standard Polarization Directed Lenses are 25 x 25mm. Our 25mm Square Rectangular Bar Clamp, #54-994, is a good choice for bench mounted applications.

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