초록 ▼

An ultrafast laser providing short output pulses having a pulse length in the femtosecond range includes a resonant cavity including a plurality folding mirrors for folding the resonant cavity to shorten its overall length. The fold-mirrors each include a plurality of layers deposited by ion-beam sp

An ultrafast laser providing short output pulses having a pulse length in the femtosecond range includes a resonant cavity including a plurality folding mirrors for folding the resonant cavity to shorten its overall length. The fold-mirrors each include a plurality of layers deposited by ion-beam sputtering onto a substrate having a surface roughness of less than about 0.5 nanometers RMS. One or more of the folding mirrors may have a negative-group-velocity-dispersion mirror for allowing the laser to operate in a pulsed mode with pulses having a length of less than 500 femtoseconds.

대표청구항 ▼

[ What is claimed is:] [1.] Laser apparatus, comprising:first and second end mirrors forming a resonant cavity for laser-light;a laser gain medium located in said resonant cavity;and at least two fold-mirrors located in said resonant cavity and cooperatively aligned with said first and second end mi

[ What is claimed is:] [1.] Laser apparatus, comprising:first and second end mirrors forming a resonant cavity for laser-light;a laser gain medium located in said resonant cavity;and at least two fold-mirrors located in said resonant cavity and cooperatively aligned with said first and second end mirrors such that laser-light circulating in said resonant cavity is reflected by said fold-mirrors in a zig-zag path therebetween, laser-light reflected once from a said fold-mirror being defined as having undergone a fold-reflection, and said cooperative alignment of said at least two fold-mirrors providing at least eight fold-reflections in one transit of laser-light from any one of said end mirrors to the other; andsaid fold-mirrors each include a plurality of layers deposited by ion-beam sputtering each having a reflectivity greater than 99.99% and at least one of said fold mirrors being an NGVD mirror.