Multiphoton excitation (MPE) microscopy has evolved significantly over the past 30 years, becoming a powerful imaging method in various life sciences. Modern techniques include fluorescence microscopy, Raman scattering, and harmonic generation. MPE is used in neuroscience, pharmaceutical development, and preclinical research. The ultrafast laser is the critical component underpinning all MPE microscopy methods. Ultrafast laser systems are crucial for in vivo tissue imaging, preclinical applications, and emerging three-photon (3P) excitation applications.
Multiphoton excitation microscopy has evolved from a scientific method to a mainstream imaging technique, with neuroscience studies being the most dominant application. Combining ytterbium gain medium and optical parametric oscillator technology, femtosecond lasers are being developed to capture brighter images from deeper tissue samples at faster frame rates. Laser manufacturers also introduce features like total power control, improving imaging performance, and simplifying system operation. The choice of wavelength depends on the needs of the application.
Researchers have developed compact lasers at 780 nm, suitable for second harmonic generation imaging of collagen fibers. Researchers are exploring deeper imaging depth using longer wavelengths in neuroscience and intravital imaging. 3P excitation, which requires higher peak power than 2P, can provide greater depth for brain imaging. However, this approach lacks integrated power modulation and dispersion precompensation. A one-box laser source should be developed to support 3P imaging.
Multiphoton microscopy is a dynamic field characterized by diverse techniques and applications. Its continued growth depends on making it accessible to the broadest possible spectrum of users rather than only laser specialists. Laser manufacturers will continue working closely with cutting-edge users to stay abreast of all key developments and support these developments with new lasers and innovative laser features.
Related Content: Light Sheet Fluorescence Microscopy Eye Exam