LBTek Achromatic Quarter-Wave Plate — MAQWP20-VIS

Achromatic Quarter-Wave Plate (SM1 Mount) — Model MAQWP20-VIS

Broadband λ/4 waveplate for 400 nm-700 nm, in SM1 lens tube.

Overview

LBTek's Achromatic Quarter-Wave Plate combines a quartz crystal and MgF₂ element pair to deliver a true λ/4 retardance across the broadband wavelength range of 400 nm-700 nm. The achromatic design compensates for material dispersion, maintaining quarter-wave retardance accuracy across the full specified band rather than at a single design wavelength. Both surfaces carry a low-reflectance V-coat (R_avg < 0.5%, 6° AOI). Each plate is supplied in a SM1 lens tube.

Key Features

• Achromatic design: uniform λ/4 retardance across 400 nm-700 nm
• Quartz crystal + MgF₂ dual-element construction
• V-coat anti-reflection: R_avg < 0.5% per surface, 6° AOI
• Delay accuracy ±λ/24 (VIS) or ±λ/100 (NIR bands)
• Transmitted Wavefront Error: λ/8 @ 633 nm
• Surface Parallelism: < 10 arcsec
• Mounted in SM1-8A lens tube (SM1 internal/external thread)

Applications

• Broadband polarization state conversion (linear ↔ circular)
• White-light interferometry and ellipsometry
• Fluorescence and multi-wavelength microscopy
• Optical coherence tomography (OCT)
• Integration with broadband polarizing beamsplitters