Abstract: The present invention provides improved capillaries that lead to increased resolution in conventional capillary-flow cytometers. The cross-sectional shape of capillaries made according to the present invention lack a center of symmetry. In some embodiments, capillaries have inner side walls that are tilted at angles with respect to the collection-system optical axis so that the widest dimension of the inner bore is closest to the collection optical system and have an outer wall closest to the collection optical system with a dimension large enough to minimize the contribution of outer-wall refraction to the collected light signal. Exemplary capillary embodiments include tubes with a rectangular outer wall and a trapezoidal inner wall, a rectangular outer wall and a triangular inner wall, triangular outer and inner walls, a triangular outer wall with a trapezoidal inner wall, and a hemispherical or rhomboid outer wall and trapezoidal or triangular inner wall.

Abstract: An apparatus for filtering an input beam of light to produce an output beam of light is provided. The apparatus facilitates tuning an input beam of light to a desired wavelength by directing the input beam of light, via a mirror, onto a diffractive optical element and returning the diffracted portion of the input beam of light as an output beam of light. The apparatus may also include a polarization recovery element adapted for receiving the input beam of light and outputting a first and second spatially offset beam of polarized light. The apparatus may also be configured as a tunable receiver by utilizing a detector to detect a characteristic of a filtered output beam. The output beam may be additionally filtered by a spatial filter.

Abstract: An apparatus comprising a first reference element having an output power that varies monotonically with input frequency over an operating frequency range and receiving at least a portion of an output beam of light from an optical source. A second reference element having an output power that is frequency dependent receives at least a portion of the output beam of light. A first optical detector measures the power of a first reference beam of light from the first reference element. A second optical detector measures the power of a second reference beam of light from the second reference element. Electronic circuitry is coupled to the first and second optical detectors for receiving first and second reference signals therefrom and producing a coarse error signal for permitting coarse adjustment and a fine error signal for permitting fine adjustment of the frequency of the output beam of light.

Abstract: An apparatus for filtering an input beam of light to produce an output beam of light is provided. The apparatus facilitates tuning an input beam of light to a desired wavelength by directing the input beam of light, via a mirror, onto a diffractive optical element and returning the diffracted portion of the input beam of light as an output beam of light. The apparatus may also include a polarization recovery element adapted for receiving the input beam of light and outputting a first and second spatially offset beam of polarized light. The apparatus may also be configured as a tunable receiver by utilizing a detector to detect a characteristic of a filtered output beam. The output beam may be additionally filtered by a spatial filter.

Abstract: In order to minimize light diffraction along the direction of switching and more particularly light diffraction into the acceptance cone of the projection optics, in the present invention, mirrors are provided which are not rectangular. Also, in order to minimize the cost of the illumination optics and the size of the display unit of the present invention, the light source is placed orthogonal to the rows (or columns) of the array, and/or the light source is placed orthogonal to a side of the frame defining the active area of the array. The incident light beam, though orthogonal to the sides of the active area, are not however, orthogonal to any substantial portion of sides of the individual mirrors in the array. Orthogonal sides cause incident light to diffract along the direction of mirror switching, and result in light ‘leakage’ into the on-state even if the mirror is in the off-state. This light diffraction decreases the contrast ratio of the mirror.

Abstract: An apparatus comprising a first reference element having an output power that varies monotonically with input frequency over an operating frequency range and receiving at least a portion of an output beam of light from an optical source. A second reference element having an output power that is frequency dependent receives at least a portion of the output beam of light. A first optical detector measures the power of a first reference beam of light from the first reference element. A second optical detector measures the power of a second reference beam of light from the second reference element. Electronic circuitry is coupled to the first and second optical detectors for receiving first and second reference signals therefrom and producing a coarse error signal for permitting coarse adjustment and a fine error signal for permitting fine adjustment of the frequency of the output beam of light.

Abstract: In order to minimize light diffraction along the direction of switching and more particularly light diffraction into the acceptance cone of the projection optics, in the present invention, mirrors are provided which are not rectangular. Also, in order to minimize the cost of the illumination optics and the size of the display unit of the present invention, the light source is placed orthogonal to the rows (or columns) of the array, and/or the light source is placed orthogonal to a side of the frame defining the active area of the array. The incident light beam, though orthogonal to the sides of the active area, are not however, orthogonal to any substantial portion of sides of the individual mirrors in the array. Orthogonal sides cause incident light to diffract along the direction of mirror switching, and result in light ‘leakage’ into the on-state even if the mirror is in the off-state. This light diffraction decreases the contrast ratio of the mirror.