摘要:
A fiber optic measurement device including an optical frequency domain reflectometer (10) performs polarization diversity detection without using a polarizing beam splitter.
摘要:
A fiber optic measurement device including an optical frequency domain reflectometer (10) performs polarization diversity detection without using a polarizing beam splitter.
摘要:
A heterodyne optical signal analyzer (HOSA) permits accurate reconstruction of an optical input signal (Es) in the time domain. In one embodiment, a vector representation of the light is used to account for two polarization states of the optical signal. The components of a heterodyne optical signal analyzer (10), including optical couplers (12), all have errors and offsets. For example, optical power detectors (16) are very sensitive to changes in polarization of the optical signal (Es) and of the reference signal (Er). Several HOSA calibration procedures including detector calibration, vector calibration, and reference signal calibration are described.
摘要:
Complex data is obtained from OFDR backscatter measurements for an optical device under test (DUT). That complex scatter pattern data may be used along with a previously-determined fiber segment pattern to identify the fiber segment within the DUT, even when the DUT is an optical network DUT that includes multiple fibers coupled to perform one or more functions. In other non-limiting example applications, the OFDR scatter pattern data can be used to identify where in the DUT a loss occurred and where in the DUT a temperature change occurred.
摘要:
The technology described here enables the use of an inexpensive laser to measure an interferometric response of an optical device under test (DUT) at reflection lengths significantly greater than the coherence length of the laser. This is particularly beneficial in practical interferometric applications where cost is a concern. In other words, inexpensive lasers having shorter coherence lengths may be used to achieve very high interferometric measurements at longer DUT reflection lengths. The technology also enables the use of such inexpensive lasers to measure Rayleigh scatter in commercial-grade, single-mode optical fiber.
摘要:
The technology described here enables the use of an inexpensive laser to measure an interferometric response of an optical device under test (DUT) at reflection lengths significantly greater than the coherence length of the laser. This is particularly beneficial in practical interferometric applications where cost is a concern. In other words, inexpensive lasers having shorter coherence lengths may be used to achieve very high interferometric measurements at longer DUT reflection lengths. The technology also enables the use of such inexpensive lasers to measure Rayleigh scatter in commercial-grade, single-mode optical fiber.
摘要:
A method and structure for terminating an optical fiber are disclosed that provide an optical fiber termination structure with a small volume and very low return loss, even when the termination is in close proximity to reflective surfaces. In one example embodiment, the optical fiber termination reduces reflections into the one or more cores to a return loss of −70 dB or less regardless of the presence of surfaces proximate the optical fiber termination. At the same time, a length of the optical fiber termination is less than 5 mm and a largest transverse dimension of the optical fiber termination is less than 325 um. The optical fiber termination is useful in fiber sensing applications in general and is particularly effective for terminating a multi-core fiber used in a distributed shape sensing application.
摘要:
A method and structure for terminating an optical fiber are disclosed that provide an optical fiber termination structure with a small volume and very low return loss, even when the termination is in close proximity to reflective surfaces. In one example embodiment, the optical fiber termination reduces reflections into the one or more cores to a return loss of −70 dB or less regardless of the presence of surfaces proximate the optical fiber termination. At the same time, a length of the optical fiber termination is less than 5 mm and a largest transverse dimension of the optical fiber termination is less than 325 um. The optical fiber termination is useful in fiber sensing applications in general and is particularly effective for terminating a multi-core fiber used in a distributed shape sensing application.
摘要:
Measurement equipment may be calibrated using two different calibration paths. An initial calibration is performed using a calibration path in which an optical element may be coupled for testing after the initial calibration. Once the initial calibration has been performed and the optical element operatively-connected in the main path for testing, one or more re-calibrations occur using another calibration path. The optical element being tested need not be de-coupled during the re-calibration. Each calibration operation produces error correction matrices which are used to correct the measurement matrix generated by the test equipment for the optical element being tested.
摘要:
Measurement equipment may be calibrated using two different calibration paths. An initial calibration is performed using a calibration path in which an optical element may be coupled for testing after the initial calibration. Once the initial calibration has been performed and the optical element operatively-connected in the main path for testing, one or more re-calibrations occur using another calibration path. The optical element being tested need not be de-coupled during the re-calibration. Each calibration operation produces error correction matrices which are used to correct the measurement matrix generated by the test equipment for the optical element being tested.