Features

• Longpass Dichroic Mirror with Minimal Absorption Losses
• 1" Round Filter
• Hard Coating Allows Easy Handling and Cleaning
• Resistant to Damage from UV Light and Chemicals

A dichroic mirror/beamsplitter functions as a 50:50 beamsplitter at its design wavelength, known as the cutoff wavelength. Thorlabs' DMLP638 Longpass Dichroic Mirror/Beamsplitter has a 638 nm cutoff wavelength and provides >90% average reflection from 580 - 621 nm and >90% average transmission from 655 – 700 nm. It has a 1" diameter and is designed for use at a 45° incident angle.

Our dichroic mirrors/beamsplitters feature a dichroic coating on one surface and an antireflection coating on the opposing surface. The side is engraved with the part number and an arrow that points toward the antireflection coating.

Dichroic mirrors/beamsplitters can be used to combine a beam that has a wavelength (or wavelength range) shorter than the design wavelength with a beam that has a wavelength (or wavelength range) longer than the design wavelength while minimizing intensity losses. Alternatively, spatially overlapping beams of different colors can be split with a single optic. This feature is commonly used in fluorescence microscopy to prevent light of the excitation wavelength from reaching the imaging detector.

Specifications

• Cutoff Wavelength: 638 nm
• Reflection Band: 580 – 621 nm
• Transmission Band: 655 – 700 nm
• AR Coating Range: 400 – 700 nm
• Damage Threshold: 1.50 J/cm² (532 nm, 10 Hz, 10 ns, Ø250 µm)

Applications

• Fluorescence Microscopy
• Splitting or Combining Two Beams of Different Wavelengths
• Filtering of Spectral Components
• Laser Applications that Require Minimal Wavefront Distortion