Fiber-based 1150-nm femtosecond laser source for the minimally invasive harmonic generation microscopy
Journal
Journal of Biomedical Optics
Journal Volume
22
Journal Issue
3
Date Issued
2017
Author(s)
Abstract
Harmonic generation microscopy (HGM) has become one unique tool of optical virtual biopsy for the diagnosis of cancer and the in vivo cytometry of leukocytes. Without labeling, HGM can reveal the submicron features of tissues and cells in vivo. For deep imaging depth and minimal invasiveness, people commonly adopt 1100- to 1300-nm femtosecond laser sources. However, those lasers are typically based on bulky oscillators whose performances are sensitive to environmental conditions. We demonstrate a fiber-based 1150-nm femtosecond laser source, with 6.5-nJ pulse energy, 86-fs pulse width, and 11.25-MHz pulse repetition rate. It was obtained by a bismuth borate or magnesium-doped periodically poled lithium niobate (MgO:PPLN) mediated frequency doubling of the 2300-nm solitons, generated from an excitation of 1550-nm femtosecond pulses on a large mode area photonic crystal fiber. Combined with a home-built laser scanned microscope and a tailor-made frame grabber, we achieve a pulse-per-pixel HGM imaging in vivo at a 30-Hz frame rate. This integrated solution has the potential to be developed as a stable HGM system for routine clinical use. ? 2017 Society of Photo-Optical Instrumentation Engineers (SPIE).
Subjects
harmonic generation microscopy; photonic crystal fiber; soliton self-frequency-shift
SDGs
Other Subjects
Crystal whiskers; Electromagnetic pulse; Fibers; Frequency doublers; Harmonic analysis; Harmonic generation; Nonlinear optics; Photonic crystal fibers; Solitons; Textile fibers; Ultrafast lasers; Ultrashort pulses; Environmental conditions; Frequency-doubling; Harmonic generation microscopy; Integrated solutions; Large-mode-area photonic crystal fibers; Minimally invasive; Periodically poled lithium niobate; Soliton self-frequency shift; Pulse repetition rate; devices; diagnostic imaging; laser; light; microscopy; photon; Diagnostic Imaging; Lasers; Light; Microscopy; Photons
Type
journal article