| System and instrument to verify routing and measure insertion losses of multiple fiber optic assemblies -> Monitor Keywords |
|
|
 
System and instrument to verify routing and measure insertion losses of multiple fiber optic assembliesSystem and instrument to verify routing and measure insertion losses of multiple fiber optic assemblies description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20060209290, System and instrument to verify routing and measure insertion losses of multiple fiber optic assemblies. Brief Patent Description - Full Patent Description - Patent Application Claims
BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to fiber optic assemblies and in particular, to a system and instrument for verifying the routing and measuring the insertion losses of multiple fiber optic assemblies. [0003] 2. Description of the Related Art [0004] The availability and proliferation of multiple fiber optical connectors has increased the complexity of cable assemblies necessary for routing the signals generated by transmission equipment into multiplexers and other local equipment. Until recently, single optical fiber cables were used to direct the signals between relevant points. In many cases this involved hundreds of cable assemblies which occupied a fair amount of space and were difficult to organize. [0005] To solve this problem, special cable arrangements like shuffles and flexible fiber circuits were introduced. Essentially, these arrangements consist of a collection of multiple fiber connectors, normally 8, 12 or more fiber MT or similar type fiber optic connectors, or a combination of multiple fiber and single fiber connectors, organized as input and output connectors. Fibers are then routed from one position in an input connector to another position in an output connector according to the specified routing requirements. By partially organizing the fibers in a ribbon fashion a very compact arrangement can be obtained. [0006] FIG. 1 shows a shuffle type cable assembly. In particular, the input side connectors 1, the output side connectors 3 and the optical fibers 3 are shown. FIG. 2 shows a flexible circuit type cable assembly. The optical fibers 2 are glued on a flexible substrate 3. Shown also are the input side connectors 1 and the output side connectors 4. [0007] Normally the specifications of these circuits involve a table showing the start and end of each fiber, from one of the many positions in a particular multiple fiber connector to one of the many positions in another particular multiple fiber connector. It is important to verify the correctness of the routing. Sometimes it is also necessary to determine the insertion loss (attenuation) introduced into the overall system by the cable assembly. This is important because of optical power budgeting considerations. [0008] In any fiber optic interconnection, some loss occurs. Insertion loss for a connector or splice is the difference in power that is seen by the insertion of the device into the system. Insertion loss (or attenuation) is defined as the difference between the optical power launched into an interconnection cable and the optical power measured at the opposite end, or mathematically as follows: Insertion Loss=10.times.log (P1/P0) dB [0009] Wherein P0 is the power of the optical signal launched into a cable, and [0010] P1 is the power of the optical signal as it passes out of the cable. [0011] At present, there are two main methods to verify that routing is correct and to measure insertion losses. The first method consists of using a set of a limited number of light sources and detectors (usually 12 of each or less). Launching and receiving cables connected on one side to these light sources and detectors on the other side, respectively, are terminated with the required connector and then mated successively with the connectors in the shuffle or flexible circuit. [0012] Only one multiple connector from the launching cable is mated with the connector in the shuffle or flexible circuit arrangement at one time. Since fibers in the arrangement could be routed arbitrarily from input to output connectors with fibers in one input connector being normally routed to one or more different output connectors, this implies that the mating of the cables has to be repeated several times for the same connectors, both in the input and output sides in order to verify the routing or measure the insertion losses. This not only increases the time and labor consuming nature of the measurement process, but the multiple operations of connecting and disconnecting might damage the fiber termination in the launching cables or the cable assembly arrangement itself. Moreover, determining the base power (P0 in the insertion loss formula) increases the complexity of the measurement. [0013] The second method involves the use of optical switches. In this case, one light source is directed to each input fiber successively by mechanically or otherwise switching the light. Similarly, the light leaving each output fiber is switched to a single detector. The drawback of this last method is that optical switches for large numbers of positions are normally mechanically driven and consequently slow and bulky. Precision requirements also tend to make them expensive. [0014] Accordingly, there is an unfilled need for a cost-effective system and instrument for quickly, easily and efficiently verifying the routing and measuring the insertion losses of multiple fiber optic assemblies. The present invention employs lasers and detectors that are currently manufactured in large quantities and relatively inexpensively so as to bypass the drawbacks of the two conventional methods mentioned above. SUMMARY OF THE INVENTION [0015] The present invention satisfies the aforementioned need by providing an instrument for verifying routing and measuring optical insertion losses in complex multiple connector, multiple fiber, cable assemblies, which limits the number of necessary mate-unmate operations of the connectors by using a number of light sources and connectors equal in quantity to the number of different fibers in the assembly. The instrument avoids the use of optical switches. [0016] In particular, an instrument is provided for verifying routing and measuring optical insertion losses in multiple connector, multiple fiber, cable assemblies comprising multiple light sources for launching light having a level of optical power through each fiber assembly at a first end of the fiber assembly. Multiple light detectors are operably connected to and correspond to the light sources at the opposite end of the fiber assembly for reading the optical power of the light passing through the fiber assembly. The light sources are operatively associated with a current source so that each light source can be made to launch the same amount of optical power into each fiber assembly. [0017] A processor is operably connected to the light sources and said light detectors for selectively activating a light source and its corresponding detector to determine the amount of optical power passing through the fiber assembly. The corresponding detector is further capable of indicating that no light has passed through the assembly and to that corresponding detector and thereby indicating a misrouted or broken fiber. The processor is further capable of selectively activating a light source and checking every detector for light erroneously launched to a detector other than the corresponding detector for that light source, so as to indicate a misrouted fiber. [0018] The processor is further capable of providing that each detector has the same responsivity. The light sources and connectors are equal in number to the quantity of fibers in the assembly so as to reduce the number of times the assembly must be connected and disconnected from the instrument. The instrument also avoids the need to use optical switches. [0019] In addition, a method is provided wherein the need to calibrate base optical powers for measuring insertion losses is reduced. Calibration is made independent of the cable assembly by introducing a mechanism to equalize base optical power for all fibers and provide a responsivity correction for all detectors. [0020] In particular, the method of measuring optical insertion losses in multiple connector multiple fiber cable assemblies comprises the following. It comprises the steps of successively attaching the launching cables of the instrument to a large area detector. The light sources that feed light to the cables are then activated one at a time. The current supplied to the light source is changed, so that the reading of the detector is the same for every launching cable. This procedure is repeated for each launching cable. [0021] Light is launched from any of the light sources into each of the detectors one at a time. The value of the current setting is retrievably stored in a table so that every time that light source is activated, the current is changed to this stored value and the light source launches the same amount of light power into a fiber being tested. The optical power reading is retrievably stored and used to determine a correcting factor for the responsivity of each detector; thereby making such instrument calibration, independent of the cable assembly being tested, by equalizing base optical power for all fibers, providing a responsivity correction for all fibers and avoiding the need to repeatedly calibrate the base optical powers of the instrument. [0022] These and other objects, advantages, and features of the present invention will be more fully understood and appreciated by reference to the written specification and appended drawings. Continue reading about System and instrument to verify routing and measure insertion losses of multiple fiber optic assemblies... Full patent description for System and instrument to verify routing and measure insertion losses of multiple fiber optic assemblies Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this System and instrument to verify routing and measure insertion losses of multiple fiber optic assemblies patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like System and instrument to verify routing and measure insertion losses of multiple fiber optic assemblies or other areas of interest. ### Previous Patent Application: Method for measuring and calibrating measurements using optical fiber distributed sensor Next Patent Application: Low height imaging system and associated methods Industry Class: Optics: measuring and testing ### FreshPatents.com Support Thank you for viewing the System and instrument to verify routing and measure insertion losses of multiple fiber optic assemblies patent info. IP-related news and info Results in 0.48369 seconds Other interesting Feshpatents.com categories: Medical: Surgery , Surgery(2) , Surgery(3) , Drug , Drug(2) , Prosthesis , Dentistry 174 |
 * Protect your Inventions * US Patent Office filing 
PATENT INFO |
|
