Abstract:
A method and apparatus for rapid measurements of far-field radiation profiles having a large dynamic range from an optical source is disclosed. Some embodiments of the apparatus include a collector coupled to a rotating hub so that the rotation of an entrance to the collector defines a plane, a detector coupled to receive light captured at the entrance to the collector, and detector electronics having a programmable gain coupled to receive a signal from the detector, Some embodiments may include a rotatable entrance mirror for reflecting light from the optical source into the plane of the entrance of the collector. In some embodiments, the optical source is fixed relative to the plane of the entrance of the collector. In some embodiments, the optical source is rotatable in the plane defined by the entrance of the collector. In some embodiments, the source can be an optical fiber. In some embodiments, the source can be a material irradiated by a laser. In order to obtain a large dynamic range, far-field data from the optical source is taken at a number of gain settings of the detector electronics and a compiled far-field radiation profile is constructed. Characterizing parameters for the optical source, such as fiber parameters for an optical fiber, can be calculated based on the compiled far-field radiation profile.
Abstract:
A technique for measuring the modal power distribution of an optical source (for example, a laser) launching pulses into a multimode fiber involves a characterization of the multimode fiber itself in terms of its differential modal delay. A reverse differential mode delay measurement is then performed to characterize the interaction of the optical source with the multimode fiber. By knowing these characteristics, the modal power distribution of the source into the fiber can then be determined by using a reconstruction algorithm.
Abstract:
The invention relates to a simple and relatively inexpensive way of determining the optical bit rate of an optical signal, which is based on the fact that different percentages of the signal will be transmitted through a narrow-band optical filter depending on the bit rate. Increasing the bit rate of an optical signal results in a broadening of the channel spectrum, therefore, if the optical filter is designed with a passband thinner than all (or all but one) of the channel widths, then signals with different bit rates will have distinctive amounts of transmitted light relative to the amount of input light. In the preferred embodiment the optical signal is divided into two sub-beams by a beam splitter, and one of the sub-beams is passed through the optical filter. The power of filtered sub-beam is compared to the power of the unfiltered sub-beam to provide a ratio, which is compared to one or more predetermined values indicative of the bit rate. The optical filter is preferably a Fabry-Perot etalon with a periodic response tuned to the ITU grid.
Abstract:
A method for the elimination of high-energy ion in an EUV light-radiating device includes irradiating a first target with a first exciting laser to produce a laser-produced plasma EUV light source and causing a high-energy ion generated simultaneously with EUV light to collide against plasma produced by irradiating a second target with a second laser to separate the high-energy ion from the orbit of the EUV light. An apparatus for the elimination of a high-energy ion in an EUV light-radiating device includes a device for irradiating a first target with a first exciting laser to produce a plasma EUV light source and induce emission of EUV light, a device for irradiating a second target with a second laser to produce plasma, and a device for causing a high-energy ion generated simultaneously with the EUV light to be delayed by difference between an ion flight time and plasma expansion time for ion elimination and collide against the plasma to separate the high-energy ion from the orbit of the EUV light.
Abstract:
An arrangement for determining the position of a light source includes a light-sensitive detector device and an arrangement for casting a shadow onto part of the light of the light source shining onto the detector device. The shadowing arrangement is formed by at least one rotationally symmetrical body.
Abstract:
A light monitoring system provides a sensing unit coupled to a luminaire. The sensing unit monitors both the input and the output of the luminaire for both current and voltage. In this manner, a variety of problems with the luminaire can be detected by the sensor and this information can be passed to monitoring equipment that is either hard-wired or remotely coupled to the sensing unit.
Abstract:
A method and apparatus for measuring a wave front aberration of a projection lens with high precision and a related calibration method. The apparatus includes: either a light source and an element producing a first point source in combination with the light source or a first point source generating part; a magnifying projection optical system projecting and magnifying a point image of the first point source projected by a test object; a detector detecting the magnified point image projected and magnified by the magnifying projection optical system; a supporting member supporting the magnifying projection optical system and the detector; a calculating part calculating a wave front aberration; and either a second point source producing element or a second point source generating part.
Abstract:
The objective of the present invention is providing a method and a simple instrument that can be used on a routine basis to accurately and quickly measure the focus position, waist radius, divergence, quality, power and power density of a laser beam. The measurement is performed by scanning a thin film of a nonlinear optical material in the focal region along the propagation direction of the beam and registering the variation of the on-axis intensity of the laser beam by a photodetector.
Abstract:
A nozzle (46) for a laser-plasma EUV radiation source that provides thermal isolation between the nozzle body (48) and the target material flowing therethrough. A target delivery tube (72) is provided that extends through the nozzle body (48). The delivery tube (72) has an expansion aperture (80) positioned behind an exit collimator (50) of the nozzle body (48). The delivery tube (72) is made of a low thermal conductivity material, such as stainless steel, and is in limited contact with the nozzle body (48) so that heating of the nozzle body (48) from the plasma does not heat the liquid target material being delivered through the delivery tube (72). The expansion aperture (80) has a smaller diameter than the exit collimator (50).
Abstract:
Methods are disclosed for quantifying blur, of a beam of an optical medium, exhibited by an optical system through which the beam of the optical medium passes. An embodiment of the method includes the step of determining, in an image plane of the optical system, respective destination positions of a number (N) of rays of the optical medium originating according to a probability distribution from respective points in an object plane of the optical system. The destination positions are projected onto an axis in a direction, in the image plane, in which blur is to be quantified. Respective coordinates of each of the destination positions on the axis are determined and the determined coordinates are ranked. Blur is calculated from a profile of the ranked coordinates.