Background
Ultrashort pulsed lasers are multi-disciplinary tools that have enabled powerful new technologies, with prominent examples in biomedicine, neuroscience, immunology, embryology, cancer research, metrology, materials processing, telecommunications, chemistry, and energy research. Unfortunately, directly accessible wavelengths are dependent on gain media of which there are not many choices. Accessing other wavelengths requires the use of expensive and bulky nonlinear frequency conversion methods. Available repetition rates are similarly constrained. The wavelength and repetition rate restrictions as well as the high-cost limit commercial applications of ultrashort pulsed lasers.
Technology Overview
Researchers at the University of Rochester have developed a technique which allows us to achieve ultrashort pulses without requiring a gain medium. This is done by forming solitons in a specially designed passive non-linear fiber resonator using linear and anomalous dispersion elements. In addition to single pulses, resonators can be designed that yield multiple pulses or even chirped pulses. The resonators can be seeded with inexpensive CW lasers or long-pulse (ns) lasers. Modulation rates are limited only by the resonator cycle time.
Benefits
- With no gain medium, wavelength restrictions are eliminated, as are expensive and bulky nonlinear frequency conversion systems.
- Restrictions on repetition rates are similarly removed.
- A proof-of-principle system has been built, capable of 120 fs pulses, which has an estimated 10x improvement in cost over a comparable system.
- The design is fiber-based so the resulting ultrashort pulsed source is both compact and robust.
Applications
Fiber femtosecond lasers in low- to mid-energy level markets.
