LBTEK Planar Microlens Array is a planar optical component based on the diffractive optical principle of liquid crystal polymers (LCP), designed for laser beam homogenization and beam shaping. It consists of a polymer thin film combined with a single N-BK7 window substrate. The arrayed phase distribution within the LCP film provides the functionality of a microlens array. The output beam profile depends on the parameters of the microlens units. By adjusting the phase period and contour of each microlens element, the divergence angle and beam spot shape of the output can be flexibly controlled, enabling various laser homogenization and beam-shaping requirements. The device is polarization-dependent: when illuminated with right- or left-handed circularly polarized light, the output beams from the microlens elements exhibit divergence or convergence. According to diffraction principles, the divergence or convergence angle of each unit lens follows sinθ = λ/p, where λ is the design wavelength and p is the radial phase period of the lens unit.

As a single-wavelength design, the microlens array is free of spherical aberration. The incident surface is coated with an antireflection (AR) layer to ensure high transmission and diffraction efficiency. It can be widely applied in systems such as wavefront sensing, light concentration, and beam shaping, and shows great potential in optical information processing, optical interconnection, optical computing, image scanning, light-field cameras, medical devices, 3D imaging, and display technologies. LBTEK provides standard microlens arrays with a diameter of Ø25.4 mm, microlens unit focal lengths of 5 mm and 50 mm, square-shaped output beams, and design wavelengths of 532 nm, 633 nm, 850 nm, 915 nm, and 976 nm.

LBTEK Planar Microlens Array is fabricated on an N-BK7 window with a single-layer substrate. One side of the substrate is coated with a liquid crystal polymer (LCP) film, providing a uniform phase retardation of λ/2 across the entire clear aperture at the design wavelength, while the opposite side is coated with an antireflection (AR) layer, which is recommended as the incident surface. The output beam profile depends on the parameters of the microlens units. For standard products, the output beam has a square shape, with the cut edge aligned parallel to one side of the square beam. LBTEK also offers customization services, and for specific requirements customers are encouraged to contact technical support. This product has a single protective substrate, and users should distinguish between the AR-coated side (incident surface) and the LCP side, with the tip of the “V” mark pointing to the LCP side. The LCP surface must be protected from scratching, rubbing, or any form of physical contact. Solvents such as alcohol, water, and acetone should not be used to wipe the LCP surface; if cleaning is required, non-contact methods such as an air gun are strongly recommended.