The Folland lab is located in 177 and 194 of the Iowa Advanced Technology Laboratories. This is a state-of-the-art facility designed for precision optical measurements. Instrumentation includes spectrometers, cryostats, 2D material handling and ultrafast laser systems. Check back for more details as we update the lab. A brief video tour performed Jan 2023 is available below
IATL 194 contains a Bruker Vertex 80V infrared spectrometer, optimized for measurements from the FIR to UV (5-28,000 cm-1, 2000μm-0.360μm), with a spectral resolution of 0.06 cm-1. These can all be conducted in a vacuum environment, ensuring zero background atmospheric absorption from water or carbon dioxide. The spectrometer is configured with both pyroelectric-, InSb and MCT-based detectors for high sensitivity coverage from the THz up to the near-IR and is designed to support user-provided detectors into the UV. By using MCT-based detectors, this IR spectrometer can measure time-resolved spectra (temporal resolution >2.5 ns), or modulation spectroscopy signals at rates exceeding 100 kHz. Using a variable-angle reflection accessory, polarized reflection spectra up to 83° angle of incidence can be performed on large (cm-scale) samples. This setup also supports prism coupled otto-type polaritonic measurements Further, this spectrometer interfaces with a home-built IR microscope setup, which allows for the analysis of samples on the scale of 10 μm-1000 μm. This external microscope system is designed to interface with both cryostats and ultrafast lasers that are available within the Folland lab (described below).
For cryogenic experiments, the Folland Lab has three optical access cryostats featuring different capabilities. An Oxford Instruments Microstat is capable of cooling samples using a closed cycle compressor to 3.5K, whilst also maintaining a short objective-sample distance for high NA microscopy. This is supported by a ColdEdge hydra closed cycle compressor. A second Advanced Research systems CS292-DMX-20 closed cycle cryostat is capable of cooling samples to 5K, without the requirement of a continuous flow cryostat.
For modulation or ultrafast experiments, the Folland lab also contains a Coherent RegA 9050 ultrafast amplifier and optical parametric amplifier (OPA). The Coherent RegA is a high-repetition rate (10-300 kHz) ultrafast laser based on a Coherent Vitara-T Ti:Sapphire oscillator, producing 50 fs, 8 μJ pulses at 800 nm. These pulses can be used to seed an OPA, capable of outputting a signal in the range 1200-1600 nm and an idler in the range of 1600-2400 nm, with 80 fs, 160 nJ pulses. These sources can be operated in an independent pump-probe setup or coupled to the FTIR for modulation spectroscopy/time-resolved FTIR.
The above primary experimental systems are supported by an extensive set of electrical and optical test equipment. This includes multiple lock-in amplifiers, oscilloscopes, optical filters and photodetectors. In addition to the optical characterization available in IATL 194, the Folland lab also has a 2D material preparation and transfer laboratory setup in IATL 177, containing a fume hood, and area for 2D materials exfoliation, a recently purchased Nanosurf Naio atomic force microscope for determining sample topography, and 2D transfer using a homebuilt microscopy setup.
