Dispersive Mirrors for Ultrafast Optics

Did You Know?

Did you know that a well-designed dispersive mirror can provide more than 99.8% reflectivity over a 200–300 nm bandwidth while simultaneously introducing a precisely controlled group delay dispersion (GDD) on the order of −50 to −100 fs² per bounce? This is achieved using a chirped multilayer dielectric stack, where layer thicknesses are systematically varied so different wavelengths penetrate to different depths before reflecting, effectively acting as a programmable dispersion element. A common misconception is that dispersion compensation in ultrafast systems must be done with prisms or grating pairs; in practice, a compact sequence of dispersive mirrors can replace bulky free-space compressors and offer better stability. The trade-off is that the GDD is highly angle- and wavelength-dependent, so even small alignment changes (≈1–2°) can significantly alter the net dispersion profile of a mirror set.
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Frequently Asked Questions

A dispersive mirror is a multilayer dielectric mirror engineered to provide a controlled group delay dispersion (GDD) versus wavelength, not just high reflectivity. Unlike standard broadband dielectric mirrors that aim for flat phase response, dispersive mirrors use tailored layer thicknesses and materials to introduce positive or negative dispersion for pulse compression, stretching, or dispersion compensation in ultrafast systems.

What Are Dispersive Mirrors?

Dispersive Mirrors are dielectric mirrors engineered to provide controlled group delay (GD) and group delay dispersion (GDD) over a defined wavelength range. Unlike standard high-reflectors, these mirrors use chirped multilayer coatings to tailor the spectral phase of reflected pulses, enabling dispersion compensation and pulse shaping in ultrafast optical systems.

Typical Dispersive Mirrors are designed for femtosecond Ti:sapphire, Yb-doped, or fiber laser systems and are specified by wavelength range, GDD profile, reflectance, and angle of incidence. They are commonly paired with broadband mirrors and output couplers in chirped-pulse amplification (CPA) and OPCPA setups.

Key Specifications to Compare

When evaluating Dispersive Mirrors on FindLight, engineers typically review:

  • Central wavelength and bandwidth: e.g., 700–900 nm for Ti:sapphire, 1000–1100 nm for Yb systems, or custom ranges.
  • GDD (fs²): Nominal negative or positive dispersion, often specified per bounce (e.g., −40 fs² to −100 fs²) and its tolerance over the operating band.
  • GD ripple: Group delay variation, critical for maintaining pulse quality and minimizing satellite pulses.
  • Reflectance (R): Typically >99% over the design bandwidth at a specified angle (often 0°, 5°, or 45°).
  • Angle of incidence and polarization: Performance for s-, p-, or unpolarized beams at defined AOI.
  • Damage threshold: Specified in mJ/cm² or GW/cm² for given pulse duration and repetition rate.
  • Substrate and aperture: Fused silica or similar substrates, clear aperture, flatness, and surface quality (e.g., 10-5 scratch-dig).

Typical Applications

Dispersive Mirrors are used for pulse compression after propagation in glass or fibers, intracavity dispersion management in mode-locked oscillators, stretcher-compressor design in CPA chains, and phase control in nonlinear frequency conversion stages.

Buyer Guidance on FindLight

On FindLight you can compare Dispersive Mirrors by wavelength range, GDD, reflectivity, AOI, and damage threshold to match your laser source and system layout. Review detailed datasheets where available, confirm compatibility with your pulse duration and fluence, and check if the GDD sign and magnitude support your target compressed pulse width.

If no listed Dispersive Mirrors exactly meet your requirements, use the request-quote functionality to contact suppliers for custom designs. You can request quotes and technical clarification directly from manufacturers without registration, streamlining specification, budgeting, and procurement for your ultrafast optics projects.