Power coupling equations for single-mode, single-polarization optical fibers with effects of leaky modes and broad-band light source

Macrobending often occurs in optical fibers that embedded in the ground due to shifting of soil or rocks in the ground causing interference in transmission. In this study used single-mode-multimode-singlemode fiber optic cable connected manually and axially measured using a light source test equipment and optical power meter and the results will be compared. The measurement results obtained the greater value of macrobending losses with the smaller the diameter of the winding, and the greater the number of turns. The highest value of macrobending losses in multimode cables is -1.48dB at 0.5cm diameter with 5 turns, highest value of macrobending losses on single mode cables is -12.73dB at 0.5cm diameter with 5 turns, lowest value of macrobending losses for multimode cables is -0.44dB at 5cm diameter with 1 twist, lowest macrobending losses in singlemode cables is -1.69dB at 5cm diameter with 1 twist. While the value of macrobending losses on axially connected SMS cables shows the highest value of macrobending losses on multimode cables is -1.12dB in diameter of 0.5cm with 5 turns, highest value of macrobending losses on singlemode cables is -1.18dB at diameter of 0.5cm with 5 turns, lowest value for macrobending losses on multimode cables is -0.66dB at 5cm in diameter with 1 twist, the smallest value for macrobending losses on singlemode cables is -0.27dB at 5cm diameter with 1 twist . The measurement results also showed that the macrobending losses of manually connected SMS cables were greater than the macrobending losses of axially connected SMS cables.

Download Full-text

Polarization coupling power in single-mode single-polarization optical fibers

Optics Letters ◽

10.1364/ol.14.001374 ◽

1989 ◽

Vol 14 (24) ◽

pp. 1374 ◽

Cited By ~ 8

Author(s):

Chao-Xiang Shi

Keyword(s):

Optical Fibers ◽

Single Mode ◽

Single Polarization

Download Full-text

Near-Field Scanning Optical Microscopy Studies of Materials and Devices

MRS Bulletin ◽

10.1557/s0883769400033777 ◽

1997 ◽

Vol 22 (8) ◽

pp. 27-30 ◽

Cited By ~ 2

Author(s):

J.W.P. Hsu

Keyword(s):

Optical Microscopy ◽

Light Source ◽

Optical Fibers ◽

Force Feedback ◽

Near Field ◽

Single Mode ◽

Field Zone ◽

Research Activities ◽

Scanning Optical Microscopy ◽

Near Field Scanning

Near-field scanning optical microscopy (NSOM) provides a means to study optical and optoelectronic properties of materials at the nanometer scale. The key to achieving resolution higher than the diffraction limit is to place a subwavelength-sized light source—e.g., an aperture—within the near-field zone of the sample. In this case, the area of the sample illuminated is determined by the aperture size and not by the wavelength (see Figure 1). An image can then be formed by moving the sample and light source with respect to each other. While the principle of near-field optics is straightforward, its realization at visible-light wavelengths was not achieved until the invention of scanning-probe techniques in the 1980s. Since Betzig et al. demonstrated in 1991 that bright subwavelength apertures can be made by tapering and metal-coating single-mode optical fibers, research activities involving NSOM have increased tremendously. The later incorporation of shear-force feedback to regulate tip-sample separation adds another strength to NSOM. Using this distance regulation, a topographic image similar to that obtained by a conventional scanning force microscope is acquired simultaneously with the optical image. This provides a way to correlate structural and physical properties at the same sample positions and greatly simplifies interpretation of the NSOM data.

Download Full-text