Set-ups are available for the measurement of charge mobility in organic materials using both the space charge limited current (SCLC) and time-of-flight (TOF) techniques. Current-voltage measurements for SCLC are made with a Keithley 2400 source-meter and data collection is automated using LabVIEW software. Time-of-flight transients are captured with a 500 MHz Agilent “Infiniium” digital storage oscilloscope and the optical source is a Laser Science, Inc. nitrogen laser with < 4 ns pulses of > 300 μJ at 337 nm. For temperature dependence studies these experiments utilize a temperature controlled sample mount which is capable of reaching + 200°C and accurate to ± 0.1°C.
B: This laboratory is equipped with laser sources for the characterization of organic photonic devices at telecommunication wavelengths. Characterization using ultra-fast pulses is carried out with a tunable (1350 nm < λ < 1600 nm) Spectra-Physics “OPAL” optical parametric oscillator capable of producing pulses of <130 fs at 83 MHz and > 150 mW average power. Resources for the characterization and manipulation of ultra-fast pulses include an auto-correlator and a computer controlled delay line.
Continuous wave sources include an Ando AQ4321D tunable source covering both the C and L bands, a 1 mW fiber coupled DFB laser at 1550 nm, and an ILX lightwave LDC-3724B laser diode and TEC driver unit for various semiconductor lasers including 980 nm pump lasers for Erbium based compounds.
Optical detection tools include discrete solid state detectors with optical chopper/lock-in amplifier (Stanford Research Systems SRS830 lock-in under computer control) and an Agilent 86140B optical spectrum analyzer with 10-pm accuracy and 30 dBm power capacity from 300 nm to 1700 nm (also under computer control).
For the manipulation of integrated photonics devices 1, 5 and 6-axis micro-positioners from Luminous Industries with 10 nm resolution are used. Alignment is done manually with the aid of an Olympus SZ60 stereo zoom microscope with 90X maximum magnification. Preparation of glass optical fibers for integrated devices is done with an Ericsson EFC11/4 fiber cleaver and Ericsson FSU-995FA fusion splicer.
Optical and electrical characterization of organic photorefractive materials is carried out using a wave-mixing optical set-up. Optical detection is with solid state detectors using an optical chopper/lock-in amplifier (Stanford Research Systems SRS830 lock-in under computer control). Light and dark conductivities of photorefractive materials are measured with a Keithley 6517A electrometer with fA resolution.