Abstract: A device comprising a fiber grating loop ringdown (FGLRD) system of analysis is disclosed. A fiber Bragg grating (FBG) or Long-Period grating (LPG) written in a section of single mode fused silica fiber is incorporated into a fiber loop. By utilizing the wing areas of the gratings' bandwidth as a wavelength dependent attenuator of the light transmission, a fiber grating loop ringdown concept is formed. One aspect of the present invention is temperature sensing, which has been demonstrated using the disclosed device. Temperature measurements in the areas of accuracy, stability, high temperature, and dynamic range are also described.

Abstract: An apparatus and method for controlling a light source used in Cavity Ring-Down Spectroscopy. The apparatus comprises a controller that generates a control signal to activate and deactivate the light source based on a comparison of an energy signal from a resonant cavity and a threshold. The light source is activated for a time period based on the stabilization time of the light source and the time necessary to provide sufficient energy to the resonant cavity. Thereafter the controller deactivates the light source for a predetermined time period by interrupting its current source so that the light energy in the cavity rings down and so that the presence of analyte can be measured. The light energy from the light source is directly coupled to the resonant cavity from the light source.

Abstract: A novel fiber ringdown (FRP) pressure sensor is provided for measuring extremely high pressures under extreme environmental conditions of cold and heat. Pressure measurements are achieved in a time domain by measuring ringdown times of emitted light through the fiber optic loop of the device. The novel FRP sensor can include a light source, such as a diode laser light source, two 2×1 fiber couplers, a section of fused silica single mode fiber, a photodetector, and an electronic control. The novel FRP sensor's performance in the areas of stability, reproducibility, dynamic range, and temperature tolerance are far above those of conventional sensors.

Abstract: Provided is a novel system for conducting elemental measurements using cavity ring-down spectroscopy (CRDS). The present invention provides sensitivity thousands of times improved over conventional devices and does so with the advantages of low power, low plasma flow rate, and the ability being sustained with various gases.

Abstract: An apparatus and method for controlling a light source used in Cavity Ring-Down Spectroscopy. The apparatus comprises a controller that generates a control signal to activate and deactivate the light source based on a comparison of an energy signal from a resonant cavity and a threshold. The light source is activated for a time period based on the stabilization time of the light source and the time necessary to provide sufficient energy to the resonant cavity. Thereafter the controller deactivates the light source for a predetermined time period by interrupting its current source so that the light energy in the cavity rings down and so that the presence of analyte can be measured. The light energy from the light source is directly coupled to the resonant cavity from the light source.

Abstract: A novel fiber ringdown (FRP) pressure sensor is provided for measuring extremely high pressures under extreme environmental conditions of cold and heat. Pressure measurements are achieved in a time domain by measuring ringdown times of emitted light through the fiber optic loop of the device. The novel FRP sensor can include a light source, such as a diode laser light source, two 2×1 fiber couplers, a section of fused silica single mode fiber, a photodetector, and an electronic control. The novel FRP sensor's performance in the areas of stability, reproducibility, dynamic range, and temperature tolerance are far above those of conventional sensors.

Abstract: Provided is a novel system for conducting elemental measurements using cavity ring-down spectroscopy (CRDS). The present invention provides sensitivity thousands of times improved over conventional devices and does so with the advantages of low power, low plasma flow rate, and the ability being sustained with various gases.

Abstract: The present invention provides an apparatus to analyze breath gas for diagnosing diabetes. The apparatus determines acetone levels in breath gas samples and provides a diagnostic results based on the acetone levels. The present invention further provides a method of using such apparatus to distinguish healthy people and patients with early diabetes or sever diabetes.

Abstract: An apparatus and method for controlling a light source used in Cavity Ring-Down Spectroscopy. The apparatus comprises a controller that generates a control signal to activate and deactivate the light source based on a comparison of an energy signal from a resonant cavity and a threshold. The light source is activated for a predetermined period based on the stabilization time of the light source and the time necessary to provide sufficient energy to the resonant cavity. Thereafter the controller deactivates the light source for a predetermined time period by interrupting its current source so that the light energy in the cavity ring downs and so that the presence of analyte can be measured. The light energy from the light source is directly coupled to the resonant cavity from the light source.