New Negative Dispersion Mirrors for Ultrafast Lasers
REO Negative Dispersion Mirrors
August 2, 2012
REO, a leading manufacturer of high volume precision optical solutions, has introduced a new series of negative Group Delay
Dispersion (GDD) mirrors for use with industrial ultrafast lasers having output in the visible or near infrared spectrum.
These mirrors can be designed to deliver GDD values as high as -5000 fs2 (with an accuracy ±10%) at the specific laser wavelength,
while also offering excellent reflectivity (>99.8%) as well as high laser damage threshold. Together, these characteristics
make these mirrors ideal for intra-cavity use in order to balance out self-phase modulation, and correct for the residual net
dispersion due to other components in the laser cavity, including mirrors, windows and crystals. They are also well-suited for
use in extra-cavity applications, such as for turning mirrors and in pulse compression systems.
Producing GDD correction optics requires thin film coating with a high degree of precision and repeatability
in terms of layer thickness and refractive index, deposited on to extremely low scatter optical surfaces.
REO employs our own enhanced superpolishing techniques to routinely achieve microroughness levels below 0.5 Å,
resulting in a scattering loss of less than 5 ppm. These substrates are coated using ion beam sputtering (IBS)
equipped with REO’s proprietary deposition monitoring technology to yield unsurpassed layer precision and low absorption.
REO negative GDD mirrors are typically supplied on fused silica substrates, in diameters of up to 3 inches,
with a flatness of λ/20 (at 633 nm), a surface quality of 10-5 over an 80% clear aperture, and zero defects (0-0) achievable
over controlled sub-apertures. Nominal incidence angles anywhere in the 0° to 45° range can be accommodated.
REO can also produce GDD compensating mirrors with a wide range of specifications on a custom basis.
Fore more information:
More Stories in Optics