Multiphoton Confocal Microscopes

The LSM 7 series from Carl Zeiss now permit the simultaneous use of two Nonlinear Optics lasers or one laser with an optical parametric oscillator (OPO). Both components are fully integrated. In dual laser systems different laser wavelengths simultaneously excite several fluorescent dyes or proteins. Without time loss, users can image specimens with one wavelength and manipulate them in the multiphoton mode with another.

An OPO increases the excitation range of multi- photon microscopy to up to 1300 nanometers and therefore covers in particular the absorption peak of red fluorescent proteins. The potentially very high light intensities of the OPO lasers interact with specific structures in the tissue, leading to a doubling and tripling of the oscillation frequency. Frequency tripling is especially visible on lipid-water boundaries – for example, between membrane and cytoplasm.