Single-cavity dual-wavelength all-fiber femtosecond laser for multimodal multiphoton microscopy.

Farhad Akhoundi,N Peyghambarian

doi:10.1364/boe.389557

Abstract

A single-cavity dual-wavelength all-fiber femtosecond laser is designed to generate 1030 nm wavelength for high resolution multiphoton imaging and 1700 nm wavelength for long penetration depth imaging. Considering two-photon and three-photon microscopy (2PM and 3PM), the proposed laser provides the single-photon wavelength equivalent to 343 nm, 515 nm, 566 nm and 850 nm, that can be employed to excite a wide variety of intrinsic fluorophores, dyes, and fluorescent proteins. Generating two excitation wavelengths from a single laser reduces the footprint and cost significantly compared to having two separate lasers. Furthermore, an all-reflective microscope is designed to eliminate the chromatic aberration while employing two excitation wavelengths. The compact all-fiber alignment-free laser design makes the overall size of the microscope appropriate for clinical applications.

Highlights

Multiphoton microscopy (MPM) has been recognized as a powerful technique for imaging of biological samples at submicron optical resolution
To simultaneously image various fluorophores with optimum sensitivity and selectivity, a multiwavelength femtosecond source is required. Such a multiphoton microscope design will expand its applications in genetics (DNA sequencing) [10], analyzing neural network architecture [11], examining various immune cells behavior [12,13], and tracking tumor cell [14]
(PM) double-stage Er-amplifier followed by a novel pulse compression method along with a PM large mode area (LMA) fiber for soliton self-frequency shift (SSFS)

Summary

Introduction

Multiphoton microscopy (MPM) has been recognized as a powerful technique for imaging of biological samples at submicron optical resolution. A Ti:sapphire or a fiber-based femtosecond laser with a single wavelength has been employed as the excitation source for MPMs [6,7,8,9]. To simultaneously image various fluorophores with optimum sensitivity and selectivity, a multiwavelength femtosecond source is required Such a multiphoton microscope design will expand its applications in genetics (DNA sequencing) [10], analyzing neural network architecture [11], examining various immune cells behavior [12,13], and tracking tumor cell [14]. A single-cavity dual-wavelength all-fiber femtosecond laser is proposed which can be employed to do simultaneous imaging of various intrinsic and extrinsic fluorophores through 2PM and 3PM modalities. A microscope with no chromatic aberration is designed to perform multimodal multiphoton imaging using these two excitation wavelengths

Laser design and characterization

Microscope design and performance analysis

Findings

Conclusion