Papers by Jonathan Acosta Knight
Science, 1998
We demonstrate a 158 fs 5.3 nJ mode-locked laser system based on a fiber oscillator, fiber amplif... more We demonstrate a 158 fs 5.3 nJ mode-locked laser system based on a fiber oscillator, fiber amplifier and fiber compressor. Dispersion compensation in the fiber oscillator was obtained with a solid-core photonic bandgap (SC-PBG) fiber spliced to standard fibers, and external compression is obtained with a hollow-core photonic bandgap (HC-PBG) fiber.
Nature, 2003
In a homogeneous medium with refractive index n, the biggest value can take is = nk, when it is a... more In a homogeneous medium with refractive index n, the biggest value can take is = nk, when it is a plane wave. Once it is confined, we must have < nk
Journal of Biophotonics, 2016
Negative curvature fibre (NCF) guides light in its core by inhibiting the coupling of core and cl... more Negative curvature fibre (NCF) guides light in its core by inhibiting the coupling of core and cladding modes. In this work, an NCF was designed and fabricated to transmit ultrashort optical pulses for multiphoton microscopy with low group velocity dispersion (GVD) at 800 nm. Its attenuation was measured to be <0.3 dB.m-1 over the range 600-850 nm and the GVD was-180±70 fs 2 .m-1 at 800 nm. Using an average fibre output power of ~20 mW and pulse repetition rate of 80 MHz, the NCF enabled pulses with a duration of <200 fs to be transmitted through a length of 1.5 m of fibre over a tuning range of 180 nm without the need for dispersion compensation. In a 4 m fibre, temporal and spectral pulse widths were maintained to within 10% of low power values up to the maximum fibre output power achievable with the laser system used of 278 mW at 700 nm, 808 mW at 800 nm and 420 mW at 860 nm. When coupled to a multiphoton microscope, it enabled imaging of ex vivo tissue using excitation wavelengths from 740 nm to 860 nm without any need for adjustments to the setup .
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Papers by Jonathan Acosta Knight