800nm Chirped Mirror CM68-25.4-6.35

Overview

The 800nm Chirped Mirror -70fs² (Ultrafast Innovations CM68) delivers precise negative group delay dispersion (GDD) of -70 fs² per bounce at 862nm center wavelength, optimized for Ti:Sapphire laser systems operating across 725–1000 nm. This moderate GDD value makes it ideal for oscillator intracavity dispersion control and multi-bounce CPA systems where fine-tuning of total dispersion is required without excessive bounce count.

With -70 fs²/bounce, this 862nm chirped mirror provides granular dispersion management—approximately 86 bounces compensate 6000 fs² of positive GVD accumulated through gain media and optics. This specification strikes an optimal balance between compact footprint and precise GDD tuning in sub-100 fs pulse compression architectures, avoiding the spatial constraints of higher-magnitude dispersive mirrors while maintaining low insertion loss.

Applications

• Ti:Sapphire oscillator intracavity dispersion compensation for sub-30 fs pulse generation with adjustable GDD through bounce number variation
• Chirped pulse amplification (CPA) compressor fine-tuning in 800nm amplifier systems requiring precise negative dispersion trimming after prism or grating stages
• OPA and OPCPA pump line dispersion management for optimizing temporal overlap between pump and signal pulses in 800nm-pumped parametric systems
• Multi-pass amplifier GDD control where accumulated B-integral and material dispersion require incremental compensation across 725–1000 nm bandwidth

Construction & Performance

Manufactured on 25.4 mm diameter, 6.35 mm thick UVFS substrate with ion beam sputtered (IBS) multilayer dielectric coating. Designed for P-polarization at 45° angle of incidence with >99.5% reflectance across the entire 725–1000 nm range. The broadband high-reflectivity coating ensures minimal loss in multi-bounce configurations while maintaining GDD compensation bandwidth. LIDT rated at 0.2 J/cm² for femtosecond pulses, suitable for oscillator and moderate amplifier fluences.

Storage & Handling

Operate at 25 °C, 40–60% RH. Clean only with >99% optical-grade ethanol and lint-free lens tissue using single-pass drag method. Avoid abrasive cloths and water.