BH-A11 Blue Transmission Mirror

BH-A11 is a 45 ° dichroic “blue-pass” mirror engineered to transmit only the blue primary (≈ 390 – 475 nm) while reflecting the entire green-to-red band for colour-separating light-engine prisms and phosphor/panel projectors. The coating delivers > 95 % transmission across the blue window, then plunges to < 0.5 % through the green and red (≈ 500 – 700 nm), preventing unwanted bleed that would desaturate the image. A controlled IR tail above 730 nm eases thermal load on downstream components without compromising visible contrast.

Key advantages

• High blue throughput (> 95 % 390 – 475 nm) – maximises luminous efficiency for laser-phosphor and UHP-lamp engines.

• Deep green-to-red rejection (< 0.5 % 500 – 700 nm) – produces razor-clean spectral separation for RGB combining prisms.

• Hard-oxide stack rated to 10 W/cm² – withstands the high-flux, high-temperature environment inside compact projectors.

• Minimal spectral shift at 45 ° AOI – preserves colour balance even as optical tolerances vary.

• Custom glass options – Borofloat®, Eagle XG, D263 T (≤ 450 °C) or soda-lime (≤ 150 °C) from 5 × 5 mm to 450 mm, 0.21 – 3.8 mm thick.

Typical applications

• 3-LCD and LCoS projection prisms – pass blue to the B-panel while reflecting R/G to their respective paths.

• Laser-phosphor wheel systems – separate blue pump light from yellow/green phosphor emission for improved colour gamut.

• Digital cinema lamp houses – dump red/IR heat to prolong integrator-rod life and reduce fan noise.

• Head-up & head-mounted displays – compact RGB combiners where low angle dispersion and high efficiency are critical.

• Spectral imaging illuminators – create pure blue excitation channels without green/red contamination.

Need samples next week or scheduled production next quarter? BH-A11 mirrors are coated, cut and shipped to your exact drawing—fast.