|Publication number||USH491 H|
|Application number||US 07/115,937|
|Publication date||Jul 5, 1988|
|Filing date||Oct 23, 1987|
|Priority date||Oct 23, 1987|
|Publication number||07115937, 115937, US H491 H, US H491H, US-H-H491, USH491 H, USH491H|
|Inventors||Michael C. Pitruzzello, Carolyn S. Randles|
|Original Assignee||The United States Of America As Represented By The Secretary Of The Army|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (21), Classifications (13)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to us of any royalties thereon.
In the past, fiber optic attenuators have been in use, but such devices are usually precision laboratory quality devices and are thus relatively large and expensive. Therefore, there is a need for an attentuator in which the optical attenuator is relatively small in size, inexpensive, and an optical attenuator in which attenuator variations of a few decibles are not critical.
Accordingly, it is an object of this invention to provide an optical attenuator which is small in size and relatively inexpensive.
Another object of this invention is to provide an optical attenuator in which attenuator variations of a few decibles are allowable and are not critical to the system in which the optical attenuator is to be used.
Still another object of this invention is to provide an optical attenuator for a system in which precision attenuation is not required.
Other objects and advantages of this invention will be obvious to those skilled in this art.
In accordance with this invention, a fiber optic attenuator is provided by inserting a small glass disk that is doped with metal on the surface thereof and polished on opposite sides of the disk with the disk placed in a fiber optic connector and between the window of the connector and the end of a fiber to attenuate the signal emanating from the fiber before it passes through the window and from the window onto a detector.
The single FIGURE of the drawing is a sectional view illustrating the fiber optic attenuator in accordance with this invention.
Referring now to the drawing, fiber optic attenuator 8 includes a connector plug 10 that is threaded at its outer periphery as illustrated and includes a detector 12 mounted at one end and internally of connector 10, a lens 14 mounted internally of detector 12, and window 16 mounted in coupling 10 for transmitting light to lens 14 for focusing the light energy onto detector 12. Fiber 18 has a connector ferrule 20 mounted therearound in a conventional manner and is adapted to be received in stepped bore 22 of connector 10 to be mounted and connected thereto. Cap connector portion 24 is connected to connector ferrule 20 in a conventional manner as illustrated and is threaded onto the outer surface of connector 10 to complete the connection between fiber 18 and bore 22 of connector 10. An attenuator disk 26 is placed at the end of fiber 18 and the opening of attenuator coupling 10 to attenuate excess signal emanating from the end of fiber 18. Attenuator disk 26 has the opposite surfaces thereof polished in a conventional manner and optical grease may be desired in the joint between attenuator disk 26 and the end of fiber 18 in some applications. Attenuator disk 26 is made of fused silica with sputtered metal thereon to accomplish the attenuation of the signal from optical fiber 18. The sputtered metal is generally aluminum or other alloy metals that are known and used in this type environment. A specific glass that can be used is commercially known BK7 which has been doped with a sputtered metal. Other commercially available glass with the proper doping can also be used.
An attenuator such as applicant's attenuator 26 is needed when the signal emanating from fiber 18 is too great for detector 12 to handle this much signal. This condition can occur when a system is designed to have a long length of fiber when in actuality the length of the fiber is reduced substantially for example to one-tenth of the designed length. In this type arrangement, the signal actually transmitted to the end of fiber 18 is too great for detector 12 to handle this much signal. Therefore, there is a need for an attenuator that can reduce the signal emanating from fiber 18 so that detector 12 will not be saturated and make it impossible to recover the transmitted video signal. In a system of this type, a few decibles of attenuation are not critical to the proper functioning of the device to recover the desired video signal.
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US4986621 *||Aug 15, 1989||Jan 22, 1991||Wandel & Goltermann Gmbh & Co.||Optical head adapted to receive a light guide plug|
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|US5243681 *||Apr 13, 1992||Sep 7, 1993||Amp Incorporated||Aperture disk attenuator for laser diode connector|
|US5309542 *||Sep 18, 1991||May 3, 1994||International Business Machines Corporation||Fiber optic transmitter modification for improved extinction ratio|
|US6061493 *||Sep 1, 1998||May 9, 2000||Methode Electronics, Inc.||Optical subassembly with attenuating plug|
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|US20020122637 *||Dec 26, 2000||Sep 5, 2002||Anderson Gene R.||Optical transmitter, receiver or transceiver module|
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|US20050196110 *||Mar 2, 2005||Sep 8, 2005||Aronson Lewis B.||Receiver optical subassembly with optical limiting element|
|EP0759568A1 *||Mar 6, 1996||Feb 26, 1997||Formex AB||A device for optical connection of an optical element, for example an optical fibre, with a lens|
|WO2002101438A2 *||Nov 20, 2001||Dec 19, 2002||Emcore Corporation||Attenuator and conditioner|
|WO2002101438A3 *||Nov 20, 2001||Nov 13, 2003||Emcore Corp||Attenuator and conditioner|
|WO2013022908A1 *||Aug 8, 2012||Feb 14, 2013||Tyco Electronics||Field-installable expanded beam connector system|
|U.S. Classification||385/140, 385/33, 385/88, 385/93|
|International Classification||G02B6/32, G02B6/26, G02B6/42|
|Cooperative Classification||G02B6/4204, G02B6/266, G02B6/32|
|European Classification||G02B6/42C3, G02B6/32, G02B6/26C2|