Ytterbium Fiber Laser Driven, Multiwavelength Femtosecond Optical System Operating in the Ultra-violet, Visible, Near-infrared and Mid-infrared

Over the past decade, revolutionary progress has been realized in ultrafast optics which is opening the door to exciting opportunities ranging from optical physics to cutting-edge optical engineering. Motivated by this research frontier, we have developed a multi-wavelength femtosecond optical system operating in the UV, visible, near-IR and mid-IR and have solved a variety of interesting challenges.;Driven by the increasing industrial demands for scalable and robust femtosecond sources, an Yb:fiber master-oscillator-power-amplifier (MOPA) operating at 1.3 W, 1035 nm, 240 fs, 40 MHz is built. As the potential solution for non-invasive vision correction at an eye-safe wavelength, we report the first demonstration of micro-machining of ophthalmic hydrogels employing an Yb:fiber laser.;The advent of photonic crystal fibers (PCFs) and supercontinuum generation (SC) has greatly expanded the wavelength scalability of laser sources. To address the limitations in spectral efficiency and coherence degradation of conventional SC, we demonstrate an efficient, low noise and robust femtosecond 1.3 ?m source based on the two zero dispersion wavelength (TZDW) PCF. Its excellent coherence property is measured for the first time employing an unbalanced Michelson interferometer we built.;Motivated by emerging applications in the mid-IR molecular "fingerprint" region, we report a novel scheme of femtosecond mid-IR generation based on frequency down-conversion from the TZDW source which successfully circumvents the energy constraints in prevalent Raman soliton based sources. With its wavelength limited to ∼5.5 mum, an improved self-phase modulation enabled tunable mid-IR system is demonstrated and its broad operating wavelengths of 4.2 -- 9 mum is validated by the Czerny-Turner mid-IR spectrometer we built. Laser projection display plays an important role in the display industry thanks to its large color gamut, small source etendue and high wall-plug efficiency. A novel speckle-free red-green-blue (RGB) source is demonstrated in a power-scalable manner which covers 192% NTSC color gamut (CIE 1976). To circumvent the shared issue in beam distortion of frequency converted visible sources, a projection illumination design based on liquid crystal on silicon (LCoS) in a telecentric architecture is reported.;Finally, a femtosecond UV source is constructed via external frequency tripling from the MOPA. The completed multi-wavelength optical system is synchronized and studied for applications including UV/mid-IR dual color imaging and black-light generation.