Microscopy and Tweezers

We have three microscope platforms (based on Leica DM-IRB and Leica DMI-4000 chassis) that have been modified to permit laser focussing at the imaging plane through either the objective or condenser lenses. Spectroscopic signals can be collected using both forward and backscattered light. The lenses are optimised for the visible range and if required a reflecting objective is available for extending pump wavelengths to 200 nm.

Optical trapping is also available with this configuration. The trap can hold and manipulate micron-sized particles using a focussed laser beam. The trapping laser can be that of the probe beam or can be a wavelength isolated from the area of spectral interest. Multiple traps can be created using acousto-optic deflection techniques.

The set-up has been used to date for the techniques below but can be modified to incorporate other techniques found in the MSD:

• Raman Tweezers
• Cavity Enhanced Droplet Spectroscopy
• Micro-transient absorption
• Whispering Gallery Modes