摘要:
The present invention relates generally to optical rotary joints (35) for enabling optical communication between a rotor and a stator, and to improved optical reflector assemblies for use in such optical rotary joints.
摘要:
The present invention relates generally to optical rotary joints (35) for enabling optical communication between a rotor and a stator, and to improved methods of mounting such optical rotary joints on supporting structures such that the rotor and stator remain properly aligned.
摘要:
An instrument for total internal reflection fluorescence spectroscopy having modular probe that inexpensively monitors vapors and liquid-phase analytes under field conditions is described. The system is particularly helpful in evaluating multiple analytes using the fluorescence of a material immobilized in a thin sorbent polymer coating. At the same time, the system is capable of monitoring trace quantities of analyte using a fluorescence-read immunological reaction. The device includes a diode laser source, a shaped optical element (which may be as simple as a microscope slide), and one or more amplified photodiode detectors. The shaped optical element propagates light from the diode laser in a series of internally reflective bounces.
摘要:
The present sensor allows the user of any diode laser structure to be employed to provide sensitive chemical and biological detector. A diode laser electrochemical sensor is described in U.S. Pat. No. 5,591,407 “Laser Diode Sensor”. The present invention surpasses the capabilities of those sensors by measuring changes in the output power, output spectral characteristics or output signal auto-correlation function to detect the presence of chemical or biological films within the sensitive region.
摘要:
An optical fiber fluorescence sensor system capable of compensating fiber bending loss is provided. The system uses a modulated light-emitting diode and digital-signal processing chips to enhance the measurement of fluorescence signals. A fiber-optic oxygen sensor system suitable for measuring oxygen levels in gas and in aqueous media is provided. The system alleviates fiber bending loss. Detection of the signal-to-noise ratio of the system which exceeds 30 dB is done by using inexpensive components.
摘要:
An apparatus and its accompanying method measures fluorescence decay, fluorescence amplitude and fluorescence polarization. The instrument includes a light emitting diode or laser diode light source, an amplified photodiode detector, and electronics and software for calculating the phase of the fluorescence from the computed inner product of the scattering and fluorescence signals. The electronics for measuring fluorescence decay includes two signal synthesizers, two downconverters, a simultaneously sampling analog-to-digital converter and means for calculating the inner product of the downconverted waveforms. A signal source, preferably a direct digital synthesizer, is used in combination with a digital-to-analog converter to provide a controllable output signal. That signal drives a modulatable light source, which is a light emitting diode, a laser diode or a combination of the two. Excitation light from the light source excites the sample fluorophore which is immobilized in a solid material. Fluorescence is detected using an amplified photodiode. The received signal is downconverted using a pair of mixers. The downconverted signals are digitized and stored. Preferably, the signals are digitized using a two-channel synchronous analog-to-digital converter controlled by a digital signal processor. Data from each channel are multiplied and summed to provide the inner product.
摘要:
The present invention relates generally to optical rotary joints (35) for enabling optical communication between a rotor and a stator, improved methods of mounting such optical rotary joints on supporting structures such that the rotor and stator remain properly aligned, and to improved optical reflector assemblies for use in such optical rotary joints. The improved optical rotary joint enables optical communication between a rotor and a stator, said rotor having a longitudinal axis, and comprises: at least one optical source (36) mounted on one of said rotor and stator for transmitting an optical signal in a radial direction with respect to the longitudinal axis; at least one first reflector (38) mounted on the other of said rotor and stator for reflecting the optical signal transmitted from the source, said first reflector comprising a concave first reflective surface (44), a line (L) in a plane taken through said first reflective surface being configured as a portion of an ellipse having first and second focal points (F1, F2), the first focal point being positioned substantially coincident with said rotor axis; a second reflector (39) having a second reflective surface (45) configured as a portion of a cone and positioned at the second focal point of the elliptical surface for receiving light reflected from said first reflective surface and for reflecting light in a different direction as a function of the apex angle of the second reflective surface; and a receiver (40) arranged to receive light reflected by the second reflective surface.
摘要:
A highly-sensitive, rapid response fluorescent probe is based on the affinity of a polymer matrix for an analyte of interest. The probe includes a polymer matrix and a dye immobilized in the matrix. The polymer matrix has an affinity for an analyte of interest and the dye has little or no sensitivity to the analyte of interest when excited by an excitation source in a free state but has significant sensitivity to the analyte of interest when excited by the excitation source when immobilized in the matrix. Sensors incorporating the polymer/fluorophore probes of the present invention have the sensitivity and rapid response needed for detection of chemical agent and biological materials. Sensors using the probes provide sensitivity to Sarin at several hundred parts per trillion in one second or less. That is a notable advance over state-of-the-art detectors that require preconcentration steps, which in turn restrict response times to one minute or more. A wide-range of near-infrared excitable fluorophores are used as sensitive probes for analytes not detectable when the fluorophores are outside the polymer matrix. The present sensors provide early warning of the presence of toxic chemicals, provides for on-line analysis of trace materials in chemical and biological processing operations and biomedical processing operations, and provides for effective biomedical and environmental monitoring.
摘要:
The vibration and electrical characterization of a piezoelectric tactor actuator is described. The actuator is a rectangular laminated flat plate with two opposite sides simply supported and two others free. Under an axial compression from the supports, the plate deforms into a stressed shallow shell. Electrical high frequency harmonic signals within relatively low-frequency bursts are applied to the piezoelectric layers. Depending on the axial compression and pre-deflection, frequency and magnitude of electrical input, the tunable actuator exhibits frequency/mode-controlled high-force over large area vibrations with intense displacement jumps. A single-degree-of-freedom model and simplified 1-D models are provided. The tactor provides efficient conversion of electrical energy into mechanical.
摘要:
The present invention relates generally to optical rotary joints (35) for enabling optical communication between a rotor and a stator, improved methods of mounting such optical rotary joints on supporting structures such that the rotor and stator remain properly aligned, and to improved optical reflector assemblies for use in such optical rotary joints. The improved optical rotary joint enables optical communication between a rotor and a stator, said rotor having a longitudinal axis, and comprises: at least one optical source (36) mounted on one of said rotor and stator for transmitting an optical signal in a radial direction with respect to the longitudinal axis; at least one first reflector (38) mounted on the other of said rotor and stator for reflecting the optical signal transmitted from the source, said first reflector comprising a concave first reflective surface (44), a line (L) in a plane taken through said first reflective surface being configured as a portion of an ellipse having first and second focal points (F1, F2), the first focal point being positioned substantially coincident with said rotor axis; a second reflector (39) having a second reflective surface (45) configured as a portion of a cone and positioned at the second focal point of the elliptical surface for receiving light reflected from said first reflective surface and for reflecting light in a different direction as a function of the apex angle of the second reflective surface; and a receiver (40) arranged to receive light reflected by the second reflective surface.