BMS-004 Beam Splitter

BMS-004 is a UV-blocking, colour-neutral VIS beamsplitter (≈ T25/R75). After a steep blue/UV turn-on around ~360–380 nm, it settles to a near-flat ~22–25 % transmission from 400–700 nm, with a small blue-edge overshoot and a gentle red lift to ~26–27 % T by ~800 nm. The result is a bright, high-contrast reflection path and a clean, low-percent transmit tap with minimal colour bias.

Key advantages

• High-reflection split – ~T22–25 / R75–78 across most of the visible keeps the primary (reflected) channel bright.

• Strong UV suppression – rapid cutoff below ~350 nm reduces stray fluorescence and sensor haze.

• Low ripple, calibration-friendly – small spectral variation simplifies exposure matching and machine-vision thresholds.

• Mild red tilt – slight rise above ~700 nm helps photodiode pick-offs without tinting mid-band colour.

• Rugged dielectric stack – abrasion and humidity resistant for stage, field, and lab environments.

• Made to fit – Borofloat®, Eagle XG, or D263 T (0.21–3.8 mm) for duty up to ~450 °C; soda-lime for ≤150 °C. Custom-cut 5–450 mm; options include rear-surface AR and a slight wedge to suppress ghosts.

Typical applications

• Machine-vision taps – send a small, stable percentage to inspection or logging while preserving the main path.

• Projectors & light engines – power/colour feedback loops with minimal heat load.

• Metrology & alignment – beam diagnostics, power pick-offs, interferometer splits.

• Microscopy & biomedical – epi-illumination sampling without UV-induced artefacts.

• Cameras & cinema – optical viewfinders and monitoring where the reflected path must stay bright.

Typical spectral behaviour (T-path)
 

400–700 nm: ~22–25 % T (flat, low ripple) · ~380 nm: transient peak ~30–32 % T · 700–800 nm: smooth rise to ~26–27 % T · <~350 nm: strong UV suppression.

Need test chips tomorrow or thousands next quarter? BMS-004 beamsplitters are coated, diced, and shipped to your exact spec—fast.