Frame-Loss-Free Optical Line Switching System for In-Service Optical Network

Tanaka, Kuniaki; Tsujimura, Tohru; Yoshida, Kôichi; Katayama, Kazunori; Azuma, Yuji; Shimizu, Mitsuaki

doi:10.1109/jlt.2009.2030520

Cited by 14 publications

(2 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have declared active FSO technology which can be improved to an optical mesh network that serves as a rural area network. 21,22) We also applied it to the switching system of non-interruptive optical fiber line, [23][24][25][26][27] and studied the adjustment technique of optical alignment for actual fiber network. [28][29][30][31][32] We are planning to apply it to longer transmission such as beyond rivers or straits.…”

Section: Introductionmentioning

confidence: 99%

Initial alignment method for free space optics laser beam

Shimada

Tashiro

Izumi

et al. 2016

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

The authors have newly proposed and constructed an active free space optics transmission system. It is equipped with a motor driven laser emitting mechanism and positioning photodiodes, and it transmits a collimated thin laser beam and accurately steers the laser beam direction. It is necessary to introduce the laser beam within sensible range of the receiver in advance of laser beam tracking control. This paper studies an estimation method of laser reaching point for initial laser beam alignment. Distributed photodiodes detect laser luminescence at respective position, and the optical axis of laser beam is analytically presumed based on the Gaussian beam optics. Computer simulation evaluates the accuracy of the proposed estimation methods, and results disclose that the methods help us to guide the laser beam to a distant receiver.

show abstract

Section: Introductionmentioning

confidence: 99%

Initial alignment method for free space optics laser beam

Shimada

Tashiro

Izumi

et al. 2016

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…It realizes ubiquitous broadband communication in the user network using direct optical coupling technique with a single-mode fiber and a free space optics system [30]. We also improved it to the switching system for non-interruptive optical fiber line and the optical alignment technique for free space optics systems [31]- [34]. That system directly emits the laser beam, which is transferred through fiber optics, in the air.…”

mentioning

confidence: 99%

Optical Axis Identification Technique for Free Space Optics Transmission

Tashiro

Shimada

Izumi

et al. 2017

IJATES

View full text Add to dashboard Cite

Abstract-This paper describes optical axis adjustment technique for an active free space optics transmission system. This system precisely controls the direction of a collimated thin laser beam using a motor driven laser emitting mechanism and positioning photodiodes. Before beginning laser beam feedback control, it is required to guide the laser beam within the range of the positioning photodiodes for initial laser beam alignment. This paper proposes an arrival position presumption method of laser beam traveling along the long distance from transmitter. A positioning sensor containing several photodiodes measures laser luminescence distribution, and analytically calculates the optical axis of laser beam according to the modified Gaussian beam optics based on four or five distributed local intensity of laser luminescence. Experiments are conducted to evaluate the accuracy of the presumption, and results reveal that the method is effective in leading the laser beam onto a distant receiver.

show abstract