Abstract: A gas detector includes a receiver configured to receive light from a light source through gas, the light source having a bandwidth on the order of an absorption linewidth of the gas, the receiver including at least a first etalon having a transmission bandwidth on the order of the absorption linewidth of the gas, the transmission bandwidth of the first etalon being substantially smaller than the bandwidth of the light source. The gas detector further includes a first detector for detecting light transmitted through the first etalon, a second detector for detecting light reflected from the first etalon, and a processor that determines the quantity of gas based on the detected transmitted and reflected light. The gas detector can further include a second etalon with a transmission bandwidth approximately equal and adjacent to the transmission bandwidth of the first etalon.

Abstract: A gas detector includes a receiver configured to receive light from a light source through gas, the light source having a bandwidth on the order of an absorption linewidth of the gas, the receiver including at least a first etalon having a transmission bandwidth on the order of the absorption linewidth of the gas, the transmission bandwidth of the first etalon being substantially smaller than the bandwidth of the light source. The gas detector further includes a first detector for detecting light transmitted through the first etalon, a second detector for detecting light reflected from the first etalon, and a processor that determines the quantity of gas based on the detected transmitted and reflected light. The gas detector can further include a second etalon with a transmission bandwidth approximately equal and adjacent to the transmission bandwidth of the first etalon.

Abstract: Thermal 3-D microstructuring of photonic structures is provided by depositing laser energy by non-linear absorption into a focal volume about each point of a substrate to be micromachined at a rate greater than the rate that it diffuses thereout to produce a point source of heat in a region of the bulk larger than the focal volume about each point that structurally alters the region of the bulk larger than the focal volume about each point, and by dragging the point source of heat thereby provided point-to-point along any linear and non-linear path to fabricate photonic structures in the bulk of the substrate. Exemplary optical waveguides and optical beamsplitters are thermally micromachined in 3-D in the bulk of a glass substrate. The total number of pulses incident to each point is controlled, either by varying the rate that the point source of heat is scanned point-to-point and/or by varying the repetition rate of the laser, to select the mode supported by the waveguide or beamsplitter to be micromachined.

Abstract: Thermal 3-D microstructuring of photonic structures is provided by depositing laser energy by non-linear absorption into a focal volume about each point of a substrate to be micromachined at a rate greater than the rate that it diffuses thereout to produce a point source of heat in a region of the bulk larger than the focal volume about each point that structurally alters the region of the bulk larger than the focal volume about each point, and by dragging the point source of heat thereby provided point-to-point along any linear and non-linear path to fabricate photonic structures in the bulk of the substrate. Exemplary optical waveguides and optical beamsplitters are thermally micromachined in 3-D in the bulk of a glass substrate. The total number of pulses incident to each point is controlled, either by varying the rate that the point source of heat is scanned point-to-point and/or by varying the repetition rate of the laser, to select the mode supported by the waveguide or beamsplitter to be micromachined.

Abstract: Thermal 3-D microstructuring of photonic structures is provided by depositing laser energy by non-linear absorption into a focal volume about each point of a substrate to be micromachined at a rate greater than the rate that it diffuses thereout to produce a point source of heat in a region of the bulk larger than the focal volume about each point that structurally alters the region of the bulk larger than the focal volume about each point, and by dragging the point source of heat thereby provided point-to-point along any linear and non-linear path to fabricate photonic structures in the bulk of the substrate. Exemplary optical waveguides and optical beamsplitters are thermally micromachined in 3-D in the bulk of a glass substrate. The total number of pulses incident to each point is controlled, either by varying the rate that the point source of heat is scanned point-to-point and/or by varying the repetition rate of the laser, to select the mode supported by the waveguide or beamsplitter to be micromachined.