Optical fiber switch

Details Optical fiber switch Optical fiber switch

1999-07-13

2001-10-23

Sanghavi, Hemang (Department: 2874)

Optical waveguides

With optical coupler

Switch

C385S017000, C385S025000, C385S031000

Reexamination Certificate

active

06307982

ABSTRACT:

BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an optical fiber switch used to the watch of an optical fiber communication system and to a light measuring instrument. In particular, the present invention relates to a multi-circuit optical fiber switch with several hundreds or more of switching circuits which is intended to increase an operating speed, enhance reliability and optical capability, make maintenance and recovery easy, and reduce a size.
2. Description of the Related Art
Papers (B-973), (B-974) and (B-975) which were reported in Electronic Society Meeting of The Institute of Electronics, Information and Communication Engineers held in 1996 proposed a multi-circuit switch having a great many number of switching circuits.
FIG. 7
, FIG.
8
and
FIG. 9
are schematic views explaining the conventional multi-circuit switch, wherein
FIG. 7
is a plan view explaining the principle of the multi-circuit switch,
FIG. 8
is a front sectional view explaining the principle of the multi-circuit switch shown in FIG.
7
and
FIG. 9
is another front sectional view explaining the principle of the multi-circuit switch, likewise. The conventional multi-circuit switch is composed of a linearly moving type multi-circuit switch using optical fibers and lined-up V-shaped-groove arrays.
A necessary number of V-shaped-groove arrays
3
,
3
. . .
3
are disposed to the rectangular member
2
of a fixed side optical fiber assembly and processed at right angles to the longitudinal direction of the rectangular member
2
. Fixed side optical fiber cables
8
,
8
. . .
8
are bonded and fixed to the rectangular member
2
so that the optical fibers
1
,
1
. . .
1
at the extreme ends of the optical fiber cables
8
are lined up in the V-shaped-groove arrays
3
. A screw rod
4
of a movable side optical fiber assembly is driven by a not shown stepping motor. A screw hole
5
is formed to a slide block
7
so that it is meshed and engaged with the screw rod
4
. The extreme end of a movable side optical fiber cable
9
and the extreme ends of the optical fibers
6
at the extreme ends of the optical fiber cables
8
are projected from the slide block
7
and fixed thereto.
FIG. 8
shows a state that the movable side optical fiber
6
is connected to the fixed side optical fiber
1
. The slide block
7
is slightly rotated in the direction of an arrow (clockwise) by a not shown actuator to thereby press the movable side optical fiber
6
against a V-shaped groove
3
and they are connected to each other while matching optical axes of the movable side optical fiber
6
and the fixed side optical fiber
1
.
FIG. 9
shows a state that the movable side optical fiber
6
is disconnected from the fixed side optical fiber
1
. The slide block
7
is slightly rotated by the not shown actuator in the direction of an arrow (counterclockwise) to thereby displace upward and move the movable side optical fiber
6
from the V-shaped groove
3
.
The conventional switch proposes to selectively connect many circuits and the optical fiber switch is arranged as a linearly moving type switch using the optical fibers and the lined-up V-shaped-groove arrays. However, there are many drawbacks to practically use the multi-circuit switch.
A first drawback is that the optical fibers are liable to be broken because they have a very thin diameter of 0.125 mm.
A second drawback is that it is difficult to cause the extreme end of the movable side optical fiber to come into intimate contact with the V-shaped groove only by the bending force of the movable side optical fiber. Further, the absolute value of insertion loss and the dispersion thereof are liable to increase because it is difficult to prevent the deposition of dust in the V-shaped groove. This fact has been confirmed by the experiment executed by the inventors of the present invention.
A third drawback is that if, for example, 1×400 switches are arranged by disposing 8-wire ribbon optical fibers at intervals of 3.2 mm in the arrangement of a multi-circuit switch, a length of 160 mm is required only by the section where the V-shaped grooves of a fixed side optical fiber mounting plate are formed. Thus, it is impossible to reduce the size of an optical fiber switch.
A fourth drawback is that when there is a difference between the coefficients of linear thermal expansion of the rectangular member
2
for mounting the fixed side optical fibers and the screw rod
4
or when these components are placed in environments having a different temperature, an amount of positional displacement between the V-shaped groove and the movable side optical fiber is increased and an increase in the number of circuits makes the positional displacement more remarkable. As a result, there is a possibility that the movable side optical fiber cannot be accurately guided into the V-shaped groove and is broken by strain.
A fifth drawback is that since the slide block
7
is driven by the screw rod
4
which is driven by the stepping motor, the operation speed of the slide block
7
cannot be made so fast. When for example, the diameter of the screw rod
4
is 6 mm and the screw pitch thereof is 1 mm, the stepping motor must make 160 revolutions to move the slide block
7
by 160 mm. Many of stepping motors used for the above purpose require 500 pulses to make one revolution. If it is supposed that the number of input control pulses is 4000 pulses/sec. when this type of the motor is used, the stepping motor makes
8
revolutions per second. As a result, 20 seconds are necessary to cause the stepping motor to make 160 revolutions even if a motor accelerating and decelerating times are not taken into consideration. Accordingly, the stepping motor is not suitable for the application which requires a high speed operation.
A sixth drawback is that in the linearly moving type multi-circuit switch which employs the optical fibers and the lined-up V-shaped arrays, there is increased probability that the optical fibers are partially broken. Therefore, the optical fibers must be replaced and repaired. However, the replacement and repair of fixed side ribbon optical fibers are not easy, although the movable side ribbon optical fibers can be relatively easily replaced and repaired.
The linearly moving type multi-circuit switch using the optical fibers and the lined-up V-groove-shaped arrays designed based on the conventional idea has problems in reliability as described above and there are many technical problems to be solved to practically use the switch. Accordingly, there has been desired to realize a multi-circuit optical fiber switch of high reliability which is designed based on a novel idea.
It is an object of the present invention to solve the problems of the conventional multi-circuit optical fiber switch described above and provide a multi-circuit optical fiber switch designed by a novel idea which has an increased operational speed, enhanced reliability and optical capability and a reduced size and can be easily maintained and repaired.
It is another object of the present invention to provide an optical fiber switch which has ferrules with fixed side optical fibers and lined-up sleeves disposed on X-Y rectilinear coordinates as well as can be driven in X- and Y-axis directions simultaneously by means of two-dimensional X-Y slide blocks which are driven in X- and Y-axis directions by stepping motors.
It is still another object of the present invention to provide a multi-circuit optical fiber switch of high reliability which is arranged such that a ferrule with a movable side optical fiber is attached to an actuator driven in a Z-axis direction and selectively inserted into a lined-up sleeve located at an arbitrary coordinate position so that it can be connected a ferrule with a fixed side optical fiber inserted into the lined-up sleeve.
It is a further object of the present invention to provide a multi-circuit optical fiber switch of high reliability which uses, as its basic components, ferrules with optical fibers and lined-up sleeves, whic

Affiliated with

Also associated with

Rating

Optical fiber switch does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Optical fiber switch, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optical fiber switch will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2573857