Ordinarily, infrared photons do not have enough energy to excite a fluorophore which emits at visible wavelengths. Multiphoton microscopy focuses an ultrafast pulse down to nanoscale dimensions, where the photon flux is so high that two infrared photons can be absorbed at once. The result is that fluorescence occurs only at the microscope focus, eliminating all the out-of-plane fluorescence that plagues conventional fluorescence microscopes.
Normal microscopes have a fundamental limit on the smallest objects they can resolve, called the diffraction limit. For a century, it was believed that this limit was unbreakable, but in the last 20 years, several methods have emerged that allow researchers to see objects smaller than the diffraction limit.
We build instruments that interface with the brain, either to control neural activity or to recover information from it. We primarily develop new types of microscope for these applications, exploiting our expertise in optical design and automation to scale to hundreds or thousands of neurons simultaneously.
One aspect of our work is to develop microfluidic devices, primarily for drug synthesis and oncological applications. Microfludic devices are tiny chips with microchannels in (tiny channels only a few times larger than the size of a cell) and these devices have several properties which make them ideal for performing chemical syntheses.
Raman microscopy uses the inelastic scattering of light to infer what a sample is made of. Light that is scattered from a sample is split into its component wavelengths and analysed; the resulting 'spectra' are characteristic of the vibrational energy levels of the molecular bonds in the sample.
Shortwave Infrared (SWIR)
Imaging can be done using wavelengths that cannot be seen by the human eye. Infrared wavelengths are very useful for seeing deeper into scattering media, like fog or biological tissue. Working with these wavelengths requires different optical elements and detectors compared to normal imaging.
We develop new algorithms to process data, optimized for a number of criteria. These criteria might include efficiency, performance, automatic application, or something else. They can also be used on-line, as part of the data-gathering process, or offline, operating on already-aquired data.