Abstract: A transmissive and/or reflective optical filter can receive input light, which can emanate from objects traveling along paths past the filter, e.g. from biological cells, viruses, colored spots or other markings on documents, and so forth. In response, the filter can provide output light in accordance with a combined transmission function that is approximately equal to a superposition or scaled superposition of a set of simpler transmission functions. The set can include two or more non-uniform transmission functions, a subset of which can be different from each other and positioned relative to each other so that the output light has time variation in accordance with each of the functions in the subset. The subset could include, for example, a random function and a periodic function, a chirp function and a periodic function, or any other suitable combination of two or more simpler functions.

Abstract: A filter arrangement can transmit and/or reflect light emanating from a moving object so that the emanating light has time variation, and the time variation can include information about the object, such as its type. For example, emanating light from segments of a path can be transmitted/reflected through positions of a filter assembly, and the transmission functions of the positions can be sufficiently different that time variation occurs in the emanating light between segments. Or emanating light from a segment can be transmitted/reflected through a filter component in which simpler transmission functions are superimposed, so that time variation occurs in the emanating light in accordance with superposition of two simpler non-uniform transmission functions. Many filter arrangements could be used, e.g. the filter component could include the filter assembly, which can have one of the simpler non-uniform transmission functions.

Abstract: A transmissive and/or reflective optical filter can receive input light, which can emanate from objects traveling along paths past the filter, e.g. from biological cells, viruses, colored spots or other markings on documents, and so forth. In response, the filter can provide output light in accordance with a combined transmission function that is approximately equal to a superposition or scaled superposition of a set of simpler transmission functions. The set can include two or more non-uniform transmission functions, a subset of which can be different from each other and positioned relative to each other so that the output light has time variation in accordance with each of the functions in the subset. The subset could include, for example, a random function and a periodic function, a chirp function and a periodic function, or any other suitable combination of two or more simpler functions.

Abstract: A filter arrangement can transmit and/or reflect light emanating from a moving object so that the emanating light has time variation, and the time variation can include information about the object, such as its type. For example, emanating light from segments of a path can be transmitted/reflected through positions of a filter assembly, and the transmission functions of the positions can be sufficiently different that time variation occurs in the emanating light between segments. Or emanating light from a segment can be transmitted/reflected through a filter component in which simpler transmission functions are superimposed, so that time variation occurs in the emanating light in accordance with superposition of two simpler non-uniform transmission functions. Many filter arrangements could be used, e.g. the filter component could include the filter assembly, which can have one of the simpler non-uniform transmission functions.