Abstract: An electrical variable optical attenuator includes a housing (1), a cover (2), an optical module (3), and a shifting device (4). The optical module comprises a reflective device (31), a graded transmittance filter (32), a filter carrier (33), and a container (38). The reflective device is an integrated piece comprising a first reflective plane (311), a second reflective plane (312), and an opening (313) movably accommodating the graded transmittance filter therein. The first and the second reflective planes are substantially perpendicular to each other. Because the first and second reflective planes are integrally formed on the reflective device, the attenuator is relatively easy to assemble. In addition, the attenuator is able to operate reliably in rugged conditions, including applications where the attenuator may be subjected to vibration, shock or extreme temperatures.

Abstract: A variable optical attenuator (10) includes a cover (2) and a housing (3) defining an interior space therebetween for accommodating an optical module (4) and a reciprocating device (5). The reciprocating device includes a carrier (53) mounted to and driven by a screw rod (55) between opposite extreme positions. A filter (6) having a varying optical density gradient is attached to the carrier (53) to be movable therewith. The optical module includes input and output optical fibers (45, 46). Light signal goes from the input fiber transmits through the filter and reflected by a reflector (42) back to the output fiber (46). By moving the filter with respect to an optical path between the reflector and the input and output fibers, the light signal is attenuated to different extent due to the varying density of the filter. The carrier forms stoppers (511, 512) on opposite sides thereof for abuttingly engaging sidewalls of the housing for preventing over-movement of the carrier with respect to the housing.

Abstract: A variable optical attenuator (10) includes a cover (2), a housing (3), an optical module (4), a reciprocating means (5), a filter (6) and a fixer (7). The filter has a varying optical density gradient and is attached to the reciprocating means. The reciprocating means includes a carrier (53) mounted to a rotatable screw rod (55) and a stopper mechanism (51). When the screw rod is rotated, the carrier with the filter mounted on it moves toward one side of the housing or another. The stopper mechanism halts the carrier ifs side ward movement when it abuts one or another of locating slots (31, 32) of the housing, preventing the filter from moving too far to either side. Optical signals coming from the input optical fiber (45) pass through a collimator (43), through the filter, and are reflected by the reflector (42) to pass again through the filter and collimator for output in the output optical fiber (46).

Abstract: A variable optical attenuator (10) includes a cover (2), a housing (3), an optical module (4), a reciprocating means (5), a filter (6) and a fixer (7). The filter has a varying optical density gradient and is attached to the reciprocating means. The reciprocating means includes a carrier (53) mounted to a rotatable screw rod (55) and a stabilizing mechanism (54) mounted on the carrier. When the screw rod is rotated, the carrier with the filter mounted on it moves toward one side of the housing or another. The stabilizing mechanism contacts the housing to prevent the carrier and the filter from rotating with the screw rod. Optical signals coming from the input optical fiber (45) pass through a collimator (43), through the filter, and are reflected by the reflector (42) to pass again through the filter and collimator for output in the output optical fiber (46).

Abstract: An optical loop-back attenuator (2) includes a frame (22), a cover (21) attached to the frame, an optical fiber (24), an optical fiber fixture (23) retaining and fixing the optical fiber, and two SC plug connectors (25) receiving and retaining opposite ends of the optical fiber therein. The frame and the cover cooperate to fittingly receive the optical fiber, the optical fiber fixture and portions of the SC plug connectors therein. The optical fiber has a bent part (242) which is configured to be semicircular or to have another suitable shape that achieves a desired attenuation.

Abstract: A variable optic attenuator includes a carrier movable in a longitudinal direction and a variable neutral density filter mounted to the carrier. A stepping motor is drivingly coupled to the carrier for reciprocally moving the filter. The carrier is coupled to a variable electric resistor for generating a feedback signal for controlling the stepping motor. A mount defines a channel in which the filter moves. The mount has two reference surfaces perpendicular to each other and 45 degree inclined with respect to the primary direction. Two mirrors are securely attached to the reference surfaces. The mount defines two bores parallel to the longitudinal direction. The bores receive and retain input and output optic fibers in precise alignment with the mirrors. A passage is formed between the mirrors and extends in a lateral direction perpendicular to the longitudinal direction and further extends through the filter.

Abstract: An optical switch (10) includes two input optical fibers (21, 22) for inputting light beams, two output optical fibers (41, 42) for receiving the light beams, a path-switching assembly (30) having a prism (321) for switching paths of the light beams, a relay (33) having a controlling circuit for controlling the path-switching assembly, two input indicators (71, 72), and two output indicators (73, 74). The path-switching assembly has a first operative state in which the prism is moved out of a path of the light beams, and a second operative state in which the prism is moved into the path. The input indicators are single color LEDs that can respectively display orange and green. The output indicators both are double color LEDs, and each can display orange and green. The output indicators instantly change color upon a change in the status of light routing of the optical switch.

Abstract: An optical switch (1) includes an optical input device (20), a plurality of optical output devices (30), a driving device (40), a movable reflection device (50) and a fixed reflection member (60) both mounted in a fixing base (70), a casing (11), and a cover (12) attached to the casing. The input device and the output devices respectively convey optical signals into and out of the optical switch. The fixed reflection member reflects incoming optical signals to the movable reflection member. The movable reflection member reflects the reflected optical signals into a desired output device. A transmitting rod (43) of the driving device drives the movable reflection member along a guide rod (53). The movable reflection member can thus be positioned to correspond to an optical path of the desired output device. Therefore, switching between a variety of output devices is easily performed.

Abstract: An optical switch (1) in accordance with the present invention includes: a housing (50), an input port (10), a plurality of output ports (11), an optical switching means (20), an indicating device (30) and a driving device (40). The optical switch includes a resistor (37), a fixed reflector (23) and a carrier (21) to which a moveable reflector (25) and a wiper contact (35) are mounted. The wiper contact slides on the surface of the resistor as the carrier moves along a pole (215), changing a resistance provided to a control circuitry. The control circuitry then provides control signals to turn on a light emitting component (31) above the output port which is optically connected with the input port.

Abstract: A variable optical attenuator (99) comprises a holder (4), a rotatable mechanism (5), a refractor (6), an input port (2) and an output port (3). The input port and the output port are engaged with corresponding upright beams (42, 43) of the holder, which hold the input port and the output port in alignment with each other. The refractor is mounted on the rotatable mechanism by adhering to or soldering on a groove (52) of the rotatable mechanism, wherein the rotatable mechanism mates with a through hole (46) of the holder to make the center of the refractor and the optical axis of input and output collimators (22, 32) of the input and output ports in line.

Abstract: An optical attenuator includes an input optical fiber (11) and an attenuating device (3). The attenuating device is a neutral density (ND) filter. The filter has a refractive index matching that of the input optical fiber, to reduce Fresnel reflectance between the attenuating device and a terminal of the input optical fiber. One surface of the ND filter is not perpendicular to an incident light beam, thus preventing multireflectance between the attenuating device and the terminal of the input optical fiber. Therefore, return loss is increased.

Abstract: An optical attenuator (100) has an optical attenuation fiber (1) doped with cobalt. Two ferrules (2A), (2B) retain the optical attenuation fiber therein. Two butting ends of the ferrules are enclosed in a flange (6), which is received in a front end of an interconnection housing (7). An alignment sleeve (4) retains a rear end of the rear ferrule and is enclosed in a rear end of the interconnection housing. A latch (8) engages with the rear end of the interconnection housing. A plug housing (9) engages with the front end of the interconnection housing. A cover (10) then attaches over all the aforesaid components. A front end of the front ferrule is exposed outside the cover, for connecting with a complementary optical connector.

Abstract: A fiber optic terminal (10) of the present invention is for protecting a pair of optical fibers (71,72) entering an optical equipment housing (90). The fiber optic terminal includes an installment section (11), an orientation section (15), a first relief portion (12) and a second relief portion (13). The first relief portion and the second relief portion are integrally molded with the installment section and the orientation section. The fiber optic terminal further defines a first passageway (121) and a second passageway (131). In assembly, the two optical fibers are received in the fiber optic terminal through the passageways to connect with optical components in the housing, and the fiber optic terminal is tightly received in the housing.

Abstract: An optical collimator (20) includes an optical fiber (21), a metal ferrule (22), a Graded Index (GRIN) lens (23) and an outer metal tube (24). The optical fiber has an exposed end (211) which is coated with metal. The exposed end of the optical fiber is inserted into the ferrule and laser welded thereto. The GRIN lens is also coated with metal. A plurality of soldering holes (241) is defined in a periphery of the outer tube. Solder is applied to the ferrule and the GRIN lens through the holes to firmly connect the outer tube, the ferrule and the GRIN lens together. After assembly, if the position of the GRIN lens or the optical fiber is found to be inaccurate, the GRIN lens and the ferrule can be easily resoldered.

Abstract: An electrical variable optical attenuator (10) includes a housing, an attenuating device (3), an optical module (4), and an electrical controlling unit (5). The housing encases the attenuating device, optical module and electrical controlling unit. The electrical controlling unit includes an electrical resistor (57), a terminal holder (56), and a stepping motor (55). The terminal holder includes a plurality of terminals (562), and a plurality of terminal sleeves (563) depending from an insulating plate (561). The terminal holders are fittingly received in positioning holes (131) defined in the housing, so that the terminals can electrically connect the stepping motor and the electrical resistor with an external power supply. The insulating plate is made of rubber, which is softer than a material of the housing. A diameter of the terminal sleeves is slightly greater than a diameter of the positioning holes. Thus the terminal sleeves provide an airtight and watertight seal.

Abstract: An electrical variable optical attenuator includes a housing (1), a cover (2), an optical module (3), and a shifting device (4). The optical module comprises a reflective device (31), a graded transmittance filter (32), a filter carrier (33), and a container (38). The reflective device is an integrated piece comprising a first reflective plane (311), a second reflective plane (312), and an opening (313) movably accommodating the graded transmittance filter therein. The first and the second reflective planes are substantially perpendicular to each other. Because the first and second reflective planes are integrally formed on the reflective device, the attenuator is relatively easy to assemble. In addition, the attenuator is able to operate reliably in rugged conditions, including applications where the attenuator may be subjected to vibration, shock or extreme temperatures.

Abstract: An optical attenuator (10) includes: an optical splitter (11), a collimator (12), two detectors (51, 52), a first and second reflectors (21, 22), an attenuating element (3) and a driving device (4). The optical splitter includes a ferrule (112) and a GRIN (graded index) lens (113). The collimator is similar to the optical splitter. Input optical signals are transmitted from an input fiber (110) through the optical splitter and are then directed to the first reflector. The optical signals reflected by the first reflector pass through the attenuating element and are subsequently reflected to the collimator by the second reflector. The two detectors receive sampling signals via an input and an output sampling fibers (111, 112). The driving device can drive the attenuating element in response to the attenuation ratio coming from the two detectors.

Abstract: An optical attenuator (8) includes: an input port (1), an output port (4), a fixed reflector (2), a movable reflector (3), two detecting means (6,7) and a driving device (5). The input port includes a first collimator (13) and a filter (10) attached to the first collimator. The output port includes a second collimator (41) and a splitter (42) connected to the second collimator. Input signals are transmitted from an input fiber (11) through the first collimator and then pass through the filter. The signals passing through the filter are directed by the fixed and the movable reflectors to the second collimator. The angular position of the movable reflector, which is driven by the driving device, determines the proportion of the signals reflected by the reflectors that are received by the second collimator, which determines the size of the output signals transmitted in the output fiber (421).

Abstract: An electrical variable optical attenuator (10) of the present invention has a housing (1), a cover (2), an attenuating means (3), an optical module (4), an electrical driving element (5), an input fiber (87) and an output fiber (86). The attenuating means includes a carrier (30) having a guide groove (301) and an inner screw (302). A filter (32) is fixed on the carrier. The optical module includes a guide pole (41). The electrical driving element has a screw rod (552), which couples with the inner screw. The attenuating means is assembled inside the optical module with the guide pole being received in the guide groove to confine the direction of movement of the carrier along the screw rod, thus helping to avoid trembling of the filter when the screw rod is rotated.