Abstract:
A radiometer includes a substrate; a radiation absorber disposed on the substrate to absorb radiation; a thermal member disposed on the substrate to change electrical resistance in response to a change in temperature of the radiometer; and a thermal link to connect the radiometer to a thermal reference, wherein the radiation absorber, the thermal member, or a combination comprising at least one of the foregoing includes a plurality of carbon nanotubes, the carbon nanotubes being mutually aligned with respect to the substrate, and the radiometer being configured to detect optical power.
Abstract:
An optical meter includes a force member to receive a force and a reflector disposed on the force member to receive radiation and to communicate a pressure of the radiation to the force member. The reflector includes a reflective surface, and the force member is configured to be displaced in response to receiving the force comprising the pressure. The optical meter is configured to measure a power of the radiation, an energy of the radiation, or a combination thereof based on the pressure. A process for measuring a property of radiation includes receiving radiation by the reflector, reflecting radiation from the reflective surface, communicating a pressure from the reflector to the force member, and displacing the force member.
Abstract:
Un appareil de mesure de la puissance de rayonnement comprend un flotteur (16) et un dispositif d'équilibrage de force (48, 50, 60, 80). Le flotteur comprend une cible (46) pour les rayonnements construite de façon telle que la force gravitationnelle nette y compris la force ascensionnelle, si elle existe, s'exerçant sur le flotteur, tend à accélérer le flotteur dans une première direction. Le dispositif d'équilibrage de force comprend un dispositif de commande (80) pour fournir un signal de commande et un dispositif (50) sensible au signal de commande pour exercer une force d'équilibrage sur le flotteur dans une deuxième direction opposée à la première, de telle sorte que l'intensité de la force d'équilibrage correspond à une caractéristique du signal de commande. Le dispositif de commande varie cette caractéristique du signal de commande, en variant ainsi la force d'équilibrage, de telle façon que lorsque le signal de commande est réglé pour provoquer la suspension du flotteur à une hauteur prédéterminée, la caractéristique du signal de commande fournit une mesure de la force exercée sur la cible lorsque le rayonnement frappe la cible, et par conséquent de la puissance du rayonnement. Le flotteur comprend de préférence un matériau magnétique (48) et le dispositif d'équilibrage de force comprend un électroaimant (50). L'appareil peut mesurer directement la force exercée sur la cible par un rayonnement acoustique ou électromagnétique, ou il peut mesurer le changement de la force ascensionnelle de la cible provoquée par le changement de la densité de la cible dû au réchauffement de celle-ci par le rayonnement électromagnétique.
Abstract:
In one aspect of the present invention, a method is provided for communicating radiation pressure provided by a light wave. The method entails positioning a reflective prism having a near total reflective surface, including an initial transparent surface and a pair of reflective surfaces each positioned at an angle relative to the initial transparent surface. Then, a light wave is directed toward the reflective prism, such that the light wave is generally normal to the transparent surface and passes therethrough. The light wave further reflects from the first and then the second reflective surface and exits the prism through the transparent surface. In this way, radiation pressure communicated by the reflecting light wave acts on the prism.
Abstract:
A photon momentum sensor includes: a reflector plate that includes: a central disk including a mirror; an annular member; a plurality of spring legs interposed between the central disk and the annular member, such that: the spring legs are interleaved; neighboring spring legs are spaced apart; and the spring legs individually are arranged in an Archimedean spiral that provides orthogonal motion of the central disk relative to the plane of the annular member; and a bias plate disposed opposing the reflector plate such that: the central disk of the reflector plate moves orthogonally to a plane of the bias plate in response to reflection of laser light, and the central disk and the bias plate are arranged spaced apart as a capacitive structure.
Abstract:
Apparatus for measuring the power of radiation that includes float means (16) and force balancing means (48, 50, 60, 80). The float means includes a target (46) for the radiation and is constructed such that the net gravitational force, including buoyancy force, if any, acting on the float means tends to accelerate the float means in a first direction. The force balancing means includes drive means (80) for providing a drive signal and means (50) responsive to the drive signal for exerting a balancing force on the float means in a second direction opposite the first direction, such that the magnitude of the balancing force corresponds to a characteristic of the drive signal. The drive means is adapted to vary such characteristic of the drive signal, to thereby vary the balancing force, such that when the drive signal is controlled so as to cause the float means to be suspended at a predetermined height, the characteristic of the drive signal provides a measure of the force exerted on a target as a result of the radiation striking the target, and therefore of the power of the radiation. The float means preferably comprises a magnetic material (48) and the force balancing means comprises an electromagnet (50). The apparatus may directly measures the force of acoustical or electromagnetic radiation on the target, or may measure the change in buoyancy of the target caused by electromagnetic radiation heating and changing the density of the target.
Abstract:
A device for measuring a light radiation pressure is provided which includes a torsion balance, a laser, a convex lens, and a line array detector. The laser is configured to emit a first laser beam. The convex lens is located on an optical path of the first laser beam and configured to focus the first laser beam to a surface of the reflector. The line array detector is configured to detect a reflected first laser beam reflected by the reflector. The disclosure also provides a method for measuring the light radiation pressure using the device.
Abstract:
An optical meter includes a force member to receive a force and a reflector disposed on the force member to receive radiation and to communicate a pressure of the radiation to the force member. The reflector includes a reflective surface, and the force member is configured to be displaced in response to receiving the force comprising the pressure. The optical meter is configured to measure a power of the radiation, an energy of the radiation, or a combination thereof based on the pressure. A process for measuring a property of radiation includes receiving radiation by the reflector, reflecting radiation from the reflective surface, communicating a pressure from the reflector to the force member, and displacing the force member.