Abstract: In an embodiment, a method includes obtaining radiation emitted from a radiation source. The method includes modulating the radiation with a time-varying modulation to generate a time-varying illumination pattern with a known modulation. The illumination pattern includes a time-varying intensity for each of a plurality of spatial locations. The method includes illuminating a target volume with the illumination pattern. The method includes collecting a signal generated by one or more objects within the target volume in response to illumination by the illumination pattern. The method includes estimating a location of each of the one or more objects based on the collected signal and the known modulation.

Abstract: In an example embodiment, a method includes emitting broad bandwidth radiation with high spatial coherence. The method includes applying a time-varying modulation to the broad bandwidth radiation. The method includes identifying optical interactions caused by the time-varying modulation of the broad bandwidth radiation. The method includes identifying one or more signals included in the optical interactions. The method includes extracting one or more respective spectral signatures associated with each respective signal of the one or more signals. The method includes determining a respective characteristic of an optically interacting material that corresponds to a respective spectral signature of the extracted spectral signatures. The method includes identifying one or more optically interacting materials by classifying one or more of the characteristics.

Abstract: An apparatus and method for measuring small changes in the centroid of the spectrum of a light field by conversion of optical frequency centroid shifts into time delays are described. A time delay for a particular frequency of light is created by directing the light into an optically dispersive system that converts the change in center frequency to a change in transit time through the system as the dispersive element causes different colors to travel at different speeds. Examples of such dispersive elements include, but are not limited to, optical fibers, bulk materials, volumetric or fiber Bragg gratings, and grating or prism based pulse stretchers. This time delay can be measured, by detecting the change in transit time (or time of flight through the dispersive element) by using a detector such as a photodiode, PMT, etc. that converts the incident optical pulse train into an electronic pulsed signal.

Abstract: Systems and methods are disclosed to determine the axial and/or lateral location of a particle using light modulated with temporal and/or spatial modulation pattern. The system, for example, may include a modulator configured to temporally modulate an intensity pattern of a line of light uniquely at each point along a lateral length of the line of light and produce an undiffracted modulated line of light, a first first-order diffracted line of light, and a second first-order diffracted line of light; and one or more optical elements configured to direct the undiffracted line of light and one of the first first-order diffracted line of light and the second first-order diffracted line of light toward at least one particle disposed at or near a sample region. The system may include a processor configured to determine an axial and/or a lateral position of the particle disposed at or near the sample region.

Abstract: An apparatus and method for measuring small changes in the centroid of the spectrum of a light field by conversion of optical frequency centroid shifts into time delays are described. A time delay for a particular frequency of light is created by directing the light into an optically dispersive system that converts the change in center frequency to a change in transit time through the system as the dispersive element causes different colors to travel at different speeds. Examples of such dispersive elements include, but are not limited to, optical fibers, bulk materials, volumetric or fiber Bragg gratings, and grating or prism based pulse stretchers. This time delay can be measured, by detecting the change in transit time (or time of flight through the dispersive element) by using a detector such as a photodiode, PMT, etc. that converts the incident optical pulse train into an electronic pulsed signal.

Abstract: Systems and methods are disclosed to determine the axial and/or lateral location of a particle using light modulated with temporal and/or spatial modulation pattern. The system, for example, may include a modulator configured to temporally modulate an intensity pattern of a line of light uniquely at each point along a lateral length of the line of light and produce an undiffracted modulated line of light, a first first-order diffracted line of light, and a second first-order diffracted line of light; and one or more optical elements configured to direct the undiffracted line of light and one of the first first-order diffracted line of light and the second first-order diffracted line of light toward at least one particle disposed at or near a sample region. The system may include a processor configured to determine an axial and/or a lateral position of the particle disposed at or near the sample region.

Abstract: Simultaneous amplitude and phase control of ultrafast laser pulses using a single, linear (one-dimensional) liquid crystal spatial light modulator is described. Amplitude shaping is accomplished by writing a high-frequency phase grating having a spatial period much smaller than the spectral focus (over-sampling), onto the modulator, and diffracting away selected frequencies in a controllable manner, while spectral phase control is imparted by adding an appropriate slow phase bias to the modulator. The close pixel spacing, large number of pixels, and small footprint of the reflective spatial light modulator employed with an angular wavelength dispersive element in a folded Martinez stretcher, enables a simple and compact apparatus to be achieved. The high reflectivity of the spatial light modulator results in a highly efficient pulse shaper when either a prism or diffractive grating is used for the angular dispersive element.