Single all-fiber-based nanosecond-pulsed supercontinuum source for multispectral photoacoustic microscopy and optical coherence tomography

Abstract

We report the usefulness of a single all-fiber-based supercontinuum (SC) source for combined photoacoustic microscopy (PAM) and optical coherence tomography (OCT). The SC light is generated by a tapered photonic crystal fiber pumped by a nanosecond pulsed master oscillator power amplifier at 1064 nm. The spectrum is split into a shorter wavelength band (500-800 nm) for single/multi-spectral PAM and a longer wavelength band (800-900 nm) band for OCT. In vivo mouse ear imaging was achieved with an integrated dual-modality system. We further demonstrated its potential for spectroscopic photoacoustic imaging by doing multispectral measurements on retinal pigment epithelium and blood samples with 15-nm linewidth.

Development of a Fiber Laser with Independently Adjustable Properties for Optical Resolution Photoacoustic Microscopy

“…The amplifier was coupled to a specially designed PCF taper that connects a large-core fiber that has a much more resistance to high-pulse energy at the input to a small-core PCF for spectrum broadening. Pulse energy per band increased dramatically and became comparable to the ones produced through SRS3945.…”

“…As can be seen, these pulse energies are quite low despite the wide bandwidths. There are many attempts to develop multiwavelength laser systems generating higher pulse energies from the output of an integrated fiber for various photoacoustic imaging applications3639404145. However, this condition requires PCFs to withstand such high energies.…”

“…For the sake of enabling spectroscopic measurements, multiwavelength spectrum is obtained from a single wavelength emitting Q-switched Nd:YAG microchip laser, either through stimulated Raman scattering (SRS) or nonlinear broadening by coupling its output to a fiber36373839404142434445. For lasers utilizing SRS, major energy is distributed on a series of fixed individual wavelength peaks that result from nonlinear interaction between incoming photons through the fiber and the molecules in the fiber itself, thus offers a limited wavelength tunability46.…”

“…Whensoever the applications by coupling the output of Q-switched Nd:YAG microchip to PCF are considered, energy per band is reported to be lower in supercontinuum case than SRS, which may be a drawback for many applications46. In order to achieve wider tunability in the wavelength with high energy per band, Shu et al 39. proposed a master oscillator power amplifier (MOPA) laser system with a homebuilt yterrbium-doped (Yb) fiber amplifier for power boost.…”

A comparative study of noise in supercontinuum light sources for ultra-high resolution optical coherence tomography

“…More specifically, its ultra-wide optical bandwidth and high average power make it an ideal tool for Optical Coherence Tomography (OCT). Over the last 5 years, numerous examples have demonstrated its high potential [3][4] in this context. However, SC light sources present pulse-to-pulse intensity variation that can limit the performance of any OCT system [5] by degrading their signal to noise ratio (SNR).…”