Optical Resources

  1. Diffuse Optical/Correlation Tomography Instrument (Adult Brain)
    • There are two identical (in functionality) instruments.Three laser diodes and drivers (675, 785, 830nm) with coupling optics and fibers are used as sources and the sources are further coupled to a series of fast, optical switches (two 1×4 prism switches, DiCoN). Furthermore, a high coherence length, external cavity laser (780nm) from Crysta Laser with a stable laser driver, optical isolator and coupling optics is also used. Two high sensitivity, fast avalanche photo diodes (APDs) and two large sensor area photomultiplier tubes (PMTs) all from Hammamatsu and eight high sensitivity, fast, photon counting APDs (Perkin-Elmer) are used as detectors. Extensive radio-frequency (RF) electronics (RF oscillators, I/Q demodulators, electronic attenuators, amplifiers, shielded cables) from Mini-Circuits are used to encode/decode signals. A custom-build (Correlator.Com) eight channel, multi-tau, correlator board is used to calculate auto-correlation functions of detected photons. Two A/D boards and two DIO boards (National Instruments) housed in a rack-mounted personal computer are used to control the instrument and record the data. A 20″ LCD screen displays the data and interface (Dell). Variety of custom-build probes housing series of fiber-optics are used with the instrument to couple the instrument to adult head. The portable instrument is housed on a 19″ rack-mount, medical instrumentation cart
  2. Diffuse Optical/Correlation Tomography Instrument (Rat Brain)
    • Five laser diodes and drivers (675, 785, 830, 915 nm) with coupling optics and fibers are used as sources and the sources are further coupled to a series of fast, optical switches (one 1×16 and one 1×8 prism switches, DiCoN). A high coherence, high power, diode-pumped, diode laser (SDL) working at 800nm is also used with an optical isolator, portable, stabilized optical bread-board and coupling optics. Eight high sensitivity, fast avalanche photo diodes (APDs) from Hammamatsu and nine high sensitivity, fast, photon counting APDs (Perkin-Elmer) are used as detectors. Extensive radio-frequency (RF) electronics (RF oscillators, I/Q demodulators, electronic attenuators, amplifiers, shielded cables) from Mini-Circuits are used to encode/decode signals. A custom-build (Correlator.Com) nine channel, multi-tau, correlator board is used to calculate auto-correlation functions of detected photons. Two personal computers are used to control the instrument and acquire data. Each has two A/D boards and two DIO boards (National Instruments) to interface with the instrument. The interface and data are displayed on two 14″ LCD screens. A custom-build fiber-optics probe (FiberOptic Systems) with a large number of fiber-optics are held in a grid coupled to the back of a modified SLR camera (FM2N, Nikon) is used to relay the light to and from the tissue. The instrument is portable on a custom-build rack mount set-up secured on an instrumentation cart.
  3. Laser Speckle/Optical Intrinsic Imaging Instrument
    • The source part consists of a collimated, laser diode (Hitachi, HL 785 1G, 785nm, 50mW, Thorlabs) driven by a custom-made driver and coupled to collimating/focusing optics and a white light, arc-lamp source (Oriel) coupled to optics and a fast, computer controlled filter-wheel (ASI) with a selection of filters between 400-650nm wavelength range. The data is acquired by a 12-Bit, TEC cooled CCD camera (QImaging, Retiga 1350EX) using imaging software (StreamPix, NorPix) coupled to a 60-mm lens (AF Micro-Nikkor 60mm f/2.8D, Nikon). Two personal computers (Dell) running in parallel are used to store the data and trigger various components. For triggering and high-precision timing an A/D board (DataWave Technologies) is used. The data is stored on a fast RAID array (320Gb) of hard drives working in parallel. The data and control interface is displayed on two 20″ LCD screens (Dell).
  4. Board Assembly Laboratory
    • The Penn HEP Engineering Group board assembly and test lab is a 400 square foot facility with state of the art tools for prototype board assembly and repair. The lab includes IR desoldering tools, robotic solder paste application tools, optical examination systems, and soldering ovens. This facility is capable of assembling or replacing fine pitch ball grid array and chip scale packages as well as the older TQFP and SOIC devices.
  5. System Test Laboratories
    • The Group also has to several electronics system testing laboratories available for use in verifying operation of advanced electronics. Tools include oscilloscopes (up to 1 GHz bandwidth), pulsers up to 300 MHz repetition rate and sub ns rise time, pattern generators, signal generators, power supplies, temperature and voltage measuring and logging systems, and a variety of VME based custom data acquisition systems. The Group also has an eighty pin, 400 MHz, Integrated Measurement Systems (IMS) model MSTS mixed analog/digital integrated circuit tester. The IMS tester is unlikely to be necessary for this work, but is a way to get a fast, extremely programmable pattern generator and logic analyzer attached to a recalcitrant system.