摘要:
A tube-encased fiber grating includes an optical fiber 10 having at least one Bragg grating 12 impressed therein which is embedded within a glass capillary tube 20. Light 14 is incident on the grating 12 and light 16 is reflected at a reflection wavelength &lgr;1. The shape of the tube 20 may be other geometries (e.g., a “dogbone” shape) and/or more than one concentric tube may be used or more than one grating or pair of gratings may be used. The fiber 10 may be doped at least between a pair of gratings 150,152, encased in the tube 20 to form a tube-encased compression-tuned fiber laser or the grating 12 or gratings 150,152 may be constructed as a tunable DFB fiber laser encased in the tube 20. Also, the tube 20 may have an inner region 22 which is tapered away from the fiber 10 to provide strain relief for the fiber 10, or the tube 20 may have tapered (or fluted) sections 27 which have an outer geometry that decreases down to the fiber 10 and provides added fiber pull strength. Also, the tube-encased grating 12 exhibits lower mode coupling from the fiber core to the cladding modes due to the increased diameter of the cladding where the tube 20 is fused to the fiber 10 where the grating is located 12.
摘要:
An apparatus and method for determining the position of a hydraulically actuated sliding sleeve valve in real time is disclosed. The apparatus comprises, in a preferred embodiment, a reference sensor and a position sensor, both of which constitute fiber optic windings wound around the hydraulic fluid cavity used to activate the sleeve. The sensors measure the pressure exerted by the hydraulic fluid in the cavity, with the reference sensor circumferentially lengthening to create an optical time delay indicative of the base line pressure of the hydraulic fluid. As the sleeve moves, the position sensor becomes increasingly exposed to the hydraulic fluid pressure and also begins to experience a time delay, which can be compared to the reference sensor's time delay to determine sleeve position.
摘要:
A sports training apparatus for training athletes to deliver a ball or other object at an appropriate arc. The sports training apparatus includes an adjustable horizontal target that is positioned between the athlete and the target. It gives guidance to the athlete at the time of release. The athlete's height, game being played, desired arc, technique employed and position on the court determine the appropriate configuration, placement, and use of the sports training apparatus described herein. Athletes use the sports training apparatus repeatedly to train, learn, and be able to repeat the desired arc for a particular shot in their sport.
摘要:
A sports training apparatus for training athletes to deliver a ball or other object at an appropriate arc. The sports training apparatus includes an adjustable horizontal target that is positioned between the athlete and the target. It gives guidance to the athlete at the time of release. The athlete's height, game being played, desired arc, technique employed and position on the court determine the appropriate configuration, placement, and use of the sports training apparatus described herein. Athletes use the sports training apparatus repeatedly to train, learn, and be able to repeat the desired arc for a particular shot in their sport.
摘要:
A sports training apparatus for training athletes to deliver a ball or other object at an appropriate arc. The sports training apparatus includes an adjustable horizontal target that is positioned between the athlete and the target. It gives guidance to the athlete at the time of release. The athlete's height, game being played, desired arc, technique employed and position on the court determine the appropriate configuration, placement, and use of the sports training apparatus described herein. Athletes use the sports training apparatus repeatedly to train, learn, and be able to repeat the desired arc for a particular shot in their sport.