Abstract: A pulse compressor. In one embodiment, the pulse compressor comprises an optical medium adapted for receiving a beam of light in an incident optical path and dispersing it into its constituent spectral colors to form a dispersed beam of light in an output optical path, where the optical medium is configured such that when an incident beam of light is received by the optical medium, it passes through the optical medium four times, in a back and forth manner, and leaves the optical medium in the form of a corresponding output beam of light.

Abstract: A new generation polarimetry apparatus and methodology is disclosed, which involve passing polarized light through a sample including a chiral analyte, where the analyte is under the influence of a periodically varying magnetic field. The apparatus also utilizes optical heterodyne detection and lock-in detection at higher order harmonics of the magnetic field modulation frequency to improve sensitivity and detection limits of optical properties of chiral analytes.

Abstract: An electromagnetic wave analyzer determines intensity and phase characteristics of an electromagnetic wave such as an ultrashort laser pulse. The analyzer passes the electromagnetic wave through a Fresnel biprism that produces a probe pulse and a gated pulse. The probe pulse and the gated pulse intersect and interact in a nonlinear optical medium, such as a second harmonic generating (SHG) crystal. The nonlinear optical medium then time gates and frequency filters the electromagnetic wave producing an input pulse gated signal. A lens maps delay in a horizontal direction and crystal output angle in a vertical direction. A camera detects the output of the lens and creates a spectrogram of the electromagnetic wave.

Abstract: An electromagnetic wave analyzer determines intensity and phase characteristics of an electromagnetic wave such as an ultrashort laser pulse. The analyzer passes the electromagnetic wave through a Fresnel biprism that produces a probe pulse and a gated pulse. The probe pulse and the gated pulse intersect and interact in a nonlinear optical medium, such as a second harmonic generating (SHG) crystal. The nonlinear optical medium then time gates and frequency filters the electromagnetic wave producing an input pulse gated signal. A lens maps delay in a horizontal direction and crystal output angle in a vertical direction. A camera detects the output of the lens and creates a spectrogram of the electromagnetic wave.

Abstract: Practical third-order frequency-resolved optical grating (FROG) techniques for characterization of ultrashort optical pulses are disclosed. The techniques are particularly suited to the measurement of single and/or weak optical pulses having pulse durations in the picosecond and subpicosecond regime. The relative quantum inefficiency of third-order nonlinear optical effects is compensated for through i) use of phase-matched transient grating beam geometry to maximize interaction length, and ii) use of interface-enhanced third-harmonic generation.

Abstract: Practical techniques are described for characterizing ultrafast potentially ultraweak, ultrashort optical pulses. The techniques are particularly suited to the measurement of signals from nonlinear optical materials characterization experiments, whose signals are generally too weak for full characterization using conventional techniques.

Abstract: A technique for making precise spectrophotometric measurements illuminates a sample with two or more modulated light sources at two or more, typically closely spaced, wavelengths. Light from the sources is combined, homogenized, and directed to the sample, and the light from the sample is collected and detected by a photodetector. The optical output powers of two sources are modulated with the same periodicity and with a reversed amplitude. Variations in the concentrations of species in the sample affect the modulation amplitude representing the sum of the optical powers from two sources in such a way as to produce an output signal. That output signal, based on an electrical component varying with a periodicity at the fundamental frequency, provides a measure of the difference in the transmissions (or other optical properties) of the sample at the two wavelengths. Feedback methods, such as null-point detection, provide stable, sensitive measurements.

Abstract: The pulse shape I(t) and phase evolution x(t) of ultrashort light pulses are obtained using an instantaneously responding nonlinear optical medium to form a signal pulse. A light pulse, such a laser pulse, is split into a gate pulse and a probe pulse, where the gate pulse is delayed relative to the probe pulse. The gate pulse and the probe pulse are combined within an instantaneously responding optical medium to form a signal pulse functionally related to a temporal slice of the gate pulse corresponding to the time delay of the probe pulse. The signal pulse is then input to a wavelength-selective device to output pulse field information comprising intensity vs. frequency for a first value of the time delay. The time delay is varied over a range of values effective to yield an intensity plot of signal intensity vs. wavelength and delay.

Abstract: The intensity and phase of one or more ultrashort light pulses are obtained using a non-linear optical medium. Information derived from the light pulses is also used to measure optical properties of materials. Various retrieval techniques are employed. Both "instantaneously" and "non-instantaneously" responding optical mediums may be used.