摘要:
A resonator for the modal control of a laser with a gain medium having a non-circular cross-section in a plane perpendicular to the optical axis of the resonator. It has a graded reflectivity mirror as the output coupler. The graded reflectivity mirror consists of a partial reflector which has a reflectivity that varies gradually according to the position on the mirror's surface. The resonator is either astigmatic or the graded reflectivity mirror has a non circularly symmetric reflectivity profile or both. It allows the production of a good optical quality beam with an efficient energy extraction.
摘要:
A low white frequency noise tunable semiconductor laser source is presented. The laser source includes a single-mode semiconductor laser assembly which generates a laser beam having a tunable frequency over a spectral range of interest. An optical filter is provided in the path of the laser beam. The optical filter has multiple spectral features distributed over the entire spectral range of interest. Each spectral feature has a narrow spectral range. A locking mechanism is further provided and is controllable for locking a spectral alignment between the frequency of the laser beam and any selected one of the spectral features of the optical filter.
摘要:
A method is provided for measuring a factor, called herein the single-port rejection ratio (SPRR), characterizing a balanced detection device. The SPRR is representative of the ratio of the weak differential output current measured under illumination of a single-port of the balanced detection device to the strong measurable differential output current obtained under dual-port illumination. An apparatus for measuring the SPRR is also provided.
摘要:
A method for fabricating a window retainer belt comprising a channel engaging edge of a window pane and a channel engaging a finish of an opening for the window pane in a body, comprising injection molding, in a single mold, a first U-shaped channel extending into a second upside down U-shaped channel, with a retention lip extending from a first inner wall of the first U-shaped channel towards an opening of the first U-shaped channel; demolding; and folding back the retention lip within the first U-shaped.
摘要:
A method for designing an index profile suitable for encoding into a phase mask for manufacturing a complex optical grating is provided. The optical grating corresponds to a target index profile defining a target spectral response. A modified index profile is set equal to the target index profile and expressed as a function of an apodization and phase profiles. The modified index profile is iteratively further modified in order to provide the index profile suitable for encoding in the phase mask. This process creates side bands outside of a spectral region of interest, while maintaining the target spectral response within the spectral region of interest.
摘要:
A method for manufacturing a complex multi-channel optical grating using a phase mask is presented. A plurality of sub-gratings is designed, each having an individual spectral response designed to produce one of the channels of the multi-channel grating. The target profile of the grating is determined based on the combination of the index profiles of the individual sub-gratings, the target index profile defining a target spectral response of the multi-channel grating. A modified index profile having a smooth apodization profile but providing the same spectral response as the target index profile, at least within a spectral region of interest, is determined and encoded into the phase mask. The phase mask is then used to photoinduce the grating in a photosensitive medium.
摘要:
A device for measuring the draft of cigarettes comprises a vertical tubular body in which cigarettes are fed one by one. A first sphincter-member mounted inside the body is operable to prevent a cigarette from falling and stop it in a given position. A second sphincter-member positioned above the first member is actuated when the first member is released so as to hold the cigarette in the above given position. A seal is provided at the bottom side of the tubular body to define a gas-tight chamber with the second sphincter-member, and an orifice connected to a source of air under vacuum is formed in the body between the first sphincter-member and the seal.
摘要:
A deployable ramp assembly including a fixed ramp portion and a pivotable ramp portion connected thereto through a direct pivot connection to pivot between stowed and deployed positions defined at a first angle from one another, a cover member pivotally connected to the fixed portion to pivot between closed and opened positions defined at a second angle from one another which is substantially smaller than the first angle, a drive assembly pivoting the cover member between the closed and opened positions, and a multiplier assembly interconnecting the pivotable portion and the cover member to transfer the pivoting motion of the cover member to the pivotable portion in an amplified manner, the multiplier assembly bringing the pivotable portion in the stowed position when the cover member is in the closed position and the pivotable portion in the deployed position when the cover member is in the opened position.
摘要:
A container having a body portion (10) and a dispensing opening, a neck (14) surrounding said dispensing opening, the neck having a rim (20), an inner neck surface (18) and an outer neck surface (16), and a drip minimizing member (32, 68) extending inwardly over a portion of the dispensing outlet, the member being located proximate the rim (20), the member terminating in a sharp edge (34, 70) to minimize dripping when pouring from the container.
摘要:
An athermally packaged optical fiber device, such as a Bragg grating, is provided. The device includes a hollow structure, and a free and a threaded member projecting in the hollow structure from both ends. The optical fiber is mounted in tension inside the hollow structure through longitudinal fiber-receiving bores in both members, and has an anchor point affixed to each member with the grating therebetween. The anchor point of the threaded member is provided outside of the hollow structure, making the device more compact. The free and threaded members are rotatable together to adjust the resonant wavelength of the grating, and a nut may be provided to allow a fine-tuning. The hollow structure, free member and threaded member have a coefficient of thermal expansion selected so that they together compensate for the temperature dependency of the Bragg wavelength.