Depending on alignment, Ultrafast Dispersing Prisms may introduce negative or positive dispersion. Negative dispersion compensation allows effects of other dispersive optical elements to be cancelled. In high-power, ultrafast applications, introducing positive dispersion elongates pulse in time to mitigate risk of damage to optical components. RoHS-compliant, 25.4 x 25.4 mm products, polished to minimize reflection loss, come in 3 substrates and support intracavity and extracavity use.