Ultrafast Optics Lab
An ultrafast laser is capable of producing optical pulses that are less than 1 picosecond (1X10-12 seconds) in duration. This remarkable tool allows us to make measurements of phenomena that occur on extremely rapid time scales. With this type of temporal resolution, we can investigate the physics of very small, nanometer (1X10-9 meters) sized objects. Here are a few snapshots from the ultrafast optics lab in room 11 in the basement of Sanders Physics:
The Pump-Probe Experiment: The pulses from an ultrafast laser can be split into two beams: a pump beam that excites the sample, and a probe beam that measures changes in the reflectivity or refractive index of the sample. A mechanical delay stage in the probe arm allows us to slightly change the arrival times of the probe pulses with respect to the pump pulses, giving us a measure of the ultrafast physics of the sample.
A peek inside the ultrafast laser: The green light from a 4W (yes, it will burn your finger, no it will not damage the rear deflector shields) diode-pumped solid state laser causes a Titanium-doped Sapphire crystal to fluoresce in the near infrared (white glow near center of photo). Through careful optical design the laser can be made to emit its optical energy in the form of very short (0.1 ps) pulses for use in a number of exciting experiments.
- An ultrafast laser capable of producing pulses that are 100 femtoseconds in duration
- An optical crysotat that allows temperature control down to a few degrees Kelvin
- COMSOL, a finite element modeling software package.