Lightmachinery Inc.

Lumonics Inc.

Edward S Williams

Ian J Miller

John H Hunter

Hubert Jean-Ruel

Jesse Dean

John Reid

Glen Gallant

Robert K Brimacombe

Vaz Zastera

Adam Donaldson

Tekai Akuetteh

Shane Boisclair

Robert W Weeks

Chris Wimperis

Conventional etalon based spectrometers have either a limited range of evaluation wavelengths or require continuous scanning of the etalon. Conventional etalon based spectrometers also have limited contrast between the peak transmission of a frequency on resonance and the minimum transmission of a frequency off resonance. An improved optical spectrometer includes a cylindrical lens configured to converge the input beam of light in only one direction, whereby the input beam of light is focused along a focal line. Accordingly, a first etalon receives the input beam of light, and transmits a series of sub-beams, each sub-beam transmitted at a different angle from the normal, and each sub-beam including multiple frequencies based on the FSR, whereby a secondary dispersive element receives each sub-beam, and disperses each sub-beam into individual frequencies. Ideally, a second etalon receives and transmits the sub-beams with increased contrast, and a second thickness of the second etalon is substantially identical to the first thickness of the first etalon.

Etalon based optical spectrometer

A conventional spatial heterodyne spectrometer (SHS) comprises a beam splitter and a pair of diffraction gratings, one in each arm of the SHS. The beam splitter separates an input beam of light into first and second sub-beams for transmission to a respective diffraction grating, and then recombines the diffracted sub-beams for focusing onto a camera. A field widened SHS enables much larger range of input angles of the original beam to be focused onto the camera, so that a broader range of wavelengths may be collected. Increasing the range of wavelengths may be provided by one or more of the following: combining the beam splitter with a field widening prism, making one diffraction grating farther from the beam splitter than the other, and placing a plurality of diffraction gratings in each arm of the SHS.

Spatial heterodyne spectrometer

The invention relates to a multi-resolution optical spectrometer that employs two output lenses of different focal length to provide a broad wavelength range, coarse resolution spectral measurement and a high resolution, lower range spectral measurement. Light dispersed by a virtual image phase array followed by a diffraction grating in two different dispersion orders may be separately focused by the two lenses upon to 2D detector array to provide the two measurements.

Multi-resolution optical spectrometer

A virtual image phase array (VIPA) includes two parallel surfaces, a first highly-reflective surface with a highly-reflective coating, and a second partially-reflective surface. The first highly-reflective surface also requires an input zone with an anti-reflection coating, which abuts the highly-reflective coating, with a transition zone therebetween. Light enters the VIPA through the input zone, and reflects back and forth between the highly and partially reflective surfaces, gradually leaking out through the partially reflective surface. To minimize the transition zone and thereby minimize the input angle of incidence and maximize the number of reflections per unit of length, the substrate coated with the highly-reflective coating is subsequently polished at an acute angle resulting in the transition zone having the same sharp angle.

Virtual image phase array

The disclosure relates to the removal of hydrogen fluoride (HF) from an excimer laser either in operation or in standby using a metal halide salt reactor. Removal of HF is desirable because the contaminant not only absorbs laser emission, thus reducing laser power, but it is also chemically reactive, and degrades the lifetime of internal laser components. The metal halide salt reactor may be provided either in the laser vessel or in an external conduit loop.

Excimer gas purification

An excimer laser system in which the expensive noble gases are reclaimed, while the halogen gas is sacrificed, and the impurities developed during operation of the excimer laser are removed. In the approach disclosed a multi-stage gas purifier is used with a single, premix gas bottle containing a halogen-rich laser gas mixture comprising noble, buffer and halogen gas, to maintain the optimum halogen content of the laser, while also maintaining a consistent ratio of noble, buffer and halogen gases without complicated control apparatus.

Excimer laser with gas purification

An excimer laser has a pair of main electrodes defining a lasing space, and a series of pairs of pre-ionization pins arranged alongside the main electrodes. These pins form preionization gaps for generating discharges that provide ultraviolet radiation to condition the gas in the lasing space. The invention consists of providing a tracker of insulating material between each pair of pins to bridge the gap and provide a tracking surface for the pre-ionization discharge.

Excimer laser

Purification of the gas mixture used in an excimer laser is carried out by cooling such mixture in a cryogenic trap to a temperature that is low enough that the lasting gas or gases (e.g. krypton, xenon, fluorine, hydrogen chloride) and the impurities are all substantially fully condensed. This temperature is nevertheless sufficiently high that the buffer gas (neon or helium or a mixture thereof) remains substantially all in gaseous form. The trap is then isolated from the laser vessel and the condensed gases therein are treated to remove at least the condensed impurities from the system. In a xenon chloride laser the condensed impurities can be effectively separated from the condensed laser gases by heating, i.e. differential distillation. After this has been done, the laser gases are returned to the laser vessel. In those instances in which such separation by differential distillation is not practicable, e.g. a krypton fluoride laser, some or all of the condensed lasing gas or gases is removed from the system together with the condensed impurities. Fresh charges of these lasing gases are then supplied to the laser vessel as required. The procedure is characterized by the fact that the buffer gas is retained and reused indefinitely. The method avoids the expense of having to periodically recharge the laser vessel with an entire fill of fresh buffer and lasing gases.

Growing community of inventors

Kanata, Canada

Edward S Williams