Studies of third-order nonlinearities in materials and devices for ultrafast lasers

Recent developments in telecommunications, frequency metrology, and medical imaging have motivated research in ultrafast optics. Demand exists for broadband components and sources as well as highly nonlinear fibers and materials. For this thesis, several different devices have been developed for such applications. Broadband saturable absorbers based on III/V and Si materials systems were developed for femtosecond lasers and have high reflectivity over 200 to 300 nm bandwidths. These absorbers were designed for modulation depths ranging from 0.3% to 18%. Self-starting modelocked operation with the absorbers was achieved in a variety of lasers including Ti:Sapphire, Cr:Forsterite, Er:glass, Cr⁴⁺:YAG and erbium-doped bismuth-oxide fiber. In tapered microstructure fiber, highly nondegenerate four-wave mixing was achieved, with a frequency shift of 6000 cm⁻¹ in an interaction length of only 1.4 cm. Amplification in erbium-doped bismuth-oxide fiber was demonstrated, with gains of 12 dB achieved between 1520 - 1600 nm in a 22.7-cm length. With a 55.6 cm length of bismuthoxide erbium-doped fiber, an L-band modelocked laser was constructed, tunable between 1570 - 1600 nm. It produced 288-fs pulses at 1600 nm. Undoped highly nonlinear bismuthoxide fiber was used to generate smooth, controlled supercontinuum between 1200 to 1800 nm.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2005

Author dc:creator

• Gopinath, Juliet Tara, 1976-

Advisor dc:contributor.advisor

• Erich P. Ippen.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/33205

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/33205