OP: High Power Widely Tunable Fiber Lasers for Nonlinear Optical Microscopy

University Of Arizona, Tucson AZ

Investigators

Abstract

Development of high power widely tunable fiber lasers for nonlinear optical microscopy of cancer and brain tissues Nontechnical description This research program will seek to improve the performance of ultrafast laser sources based on fiber format by extending the operating wavelength to new regions. A successful outcome of this program will allow the development of useful instruments with new capabilities through the use of widely tunable wavelengths, energetic, and ultrashort optical pulses. These instruments will have transformative impact on the biomedical imaging and research community by providing advanced capabilities such as on-demand wavelength tuning, access to difficult spectral regions, synchronized ultrafast laser pulses for pump/probe spectroscopy. From an educational perspective, this research will allow the PI to educate PhD graduates in the fields of Ultrafast Lasers and Fiber Lasers through the established educational programs at the College of Optical Sciences, The University of Arizona. Graduate education will be further improved by incorporating the research results into two graduate courses. In future as in previous summer months, undergraduate students will be involved in research on ultrafast fiber lasers and their applications. The PI will involve students from underrepresented groups (Native Americans, women) in his research through year round mentoring and internships, and by participating in various NSF funded outreach programs such as "Optical Sciences summer Camp", "Hooked on Photonics", "Integrated Optics for Undergraduates", and "Research Experience for Teachers" Technical description The purpose of this project is to investigate high performance widely tunable synchronously pumped ultrafast fiber optical parametric oscillators exhibiting new pulse evolutions in the cavity. The combination of standard optical gain and parametric interaction in a single laser cavity not only opens route to high output power operation but also gives rise to new dynamics never studied before. The project will address a number of key issues that currently prevent this laser platform from becoming suitable for nonlinear microscopy application. The specific goals of this proposal are: 1) Develop compact and robust ultrafast fiber lasers that can replace expensive and bulky Ti:sapphire femtosecond laser; 2) Generate ultrafast laser wavelengths not currently available commercially (in fiber format) such as 1300 nm and 1700 nm which are important for deep tissue multiphoton imaging; 3) Characterize and test the developed laser sources on real applications including cancer and brain imaging. This project will provide the first systematic study of ultrafast fiber optical parametric oscillators both experimentally and theoretically. The research will enable new high power fiber lasers working at important wavelength gaps that current state-of-the-art fiber laser technology cannot provide. Recently, fiber lasers based on traditional gain media operating in normal dispersion regime with self-similar pulse-shaping have been introduced. This has enabled fiber lasers to achieve high energy, high power, and low noise performance surpassing that of other solid-state lasers based on crystals and free-space optics. We have shown that fiber optical parametric oscillators can be designed to work in self-similar regime. The self-similar evolution opens new routes to create compact and robust optical parametric oscillators with very broad wavelength tuning and high output power level suitable for nonlinear optical microscopy and a range of other applications such as 3D writing, pump/probe spectroscopy, frequency comb metrology.