passes though the input lens 3-1 which focuses and passes the input light beam 8 toward a reflector or mirror 10. The input light beam 8 striking the surface of the reflector or mirror 10 is reflected thereby as an output light beam 12 which passes through the output lens 3-2 of the lens means 3 which focuses and passes the output light beam 12 to the output optical fiber 6.

In an example, starting from the state shown in FIG. 2A where the reflector or mirror 10 may be disposed or positioned completely in the path of the input light beam 8, whereupon the input light beam 8 received from the input optical fiber 6 is focused by the input lens 3-1 and is reflected by the reflector or mirror 10 as the output light beam 12 which is focused by the output lens 3-2 and provided to the output optical fiber 6.

If it is determined, either manually (e.g., empirically) or via the optional controller 22 from the values of electrical signals output by one or both of the optional photodiodes 16 and 18 (shown in FIG. 1A), that the output light beam 12 has too much or too great of a brightness or intensity, the reflector or mirror 10 may be moved, e.g., in the direction of arrow 24, partially out of the path of the input light beam 8 as shown in FIG. 2B. In response to this movement, the reflector or mirror 10 partially passes a portion 26 of the input light beam 8 via an edge of the reflector or mirror 10 and reflects the remainder of the input light beam 8 not passed via the edge of the reflector or mirror 10 to the output lens 3-2 and the output optical fiber 6 as the output light beam 12. In this example, the portion 26 of the input light beam 8 passed by the reflector or mirror 10 is not used.

For the purpose of illustration, in FIG. 2B the input light beam 8 prior to being partially passed and partially reflected by the reflector or mirror 10 is shown by a heavier line weight (indicative of the greater brightness or intensity of the input light beam 8 approaching the reflector or mirror 10) while the portion 26 of the input light beam 8 passed by reflector or mirror 10 and the portion of the input light beam 8 reflected by the reflector or mirror 10 as the output light beam 12 are shown by lighter line weights (indicative of a reduced brightness or intensity of the portion 26 of the input light beam 8 passed by the reflector or mirror 10 and the portion of the input light beam 8 reflected by the reflector or mirror 10 as the output light beam 12).

As can be seen, the brightness or intensity of the output light beam 12 may be controlled by selectively moving the reflector or mirror 10 as needed and/or desired to reflect as little or as much of the input light beam 8 to achieve a desired level of attenuation between the input and output light beams 8 and 12.

As shown in FIG. 2C, if desired, the reflector or mirror 10 may be moved entirely out of the path of the input light beam 8, such that the VOA 2 achieves complete attenuation of the input light beam 8 whereupon there is no output light beam 12.

With reference to FIGS. 3A-3D, another example variable optical attenuator (VOA) 2 in accordance with the principles of the present disclosure may comprise a lens means 3 optically coupled to input and output optical fibers 4 and 6, e.g., via a dual pigtail (shown e.g. in FIG. 1A). In an example, the lens means 3 may comprise input and output lenses 3-1 and 3-2 (shown in phantom) optically coupled to the input and output optical fibers 4 and 6, respectively. The lens means 3 may comprise a lens array that includes the input and output lenses 3-1 and 3-2.

An input light beam 8 exiting the input optical fiber 4 passes though the input lens 3-1 which focuses and passes the input light beam 8 toward a rotating reflector or mirror 10. The input light beam 8 impinging on the rotating reflector or mirror 10 is reflected thereby to a cylindrical lens 32. The rotating reflector or mirror 10 is configured to cause the input light beam 8 reflected thereby to diverge 30, e.g., in a cone shape, to the cylindrical lens 32 which separates the diverging 30 input light beam 8 received at different parts of an input face 34 of the cylindrical lens 32 into a plurality of parallel beams of light 36 that are output via an output face 38 of the cylindrical lens 32 to a reflector 40.

In an example, the reflector 40 may be positioned to reflect or return a first part or portion 42 of the parallel beams of light 36 output by the output face 38 of the cylindrical lens 32 back to the output face 38 of the cylindrical lens 32 and to pass a second part or portion 44 of the parallel beams of light 36 output by the output face 38 of the cylindrical lens 32. In this example, the second part or portion 44 of the parallel beams of light 36 output by the output face 38 of the cylindrical lens 32 and passed by the reflector or mirror 40 is not used.

The cylindrical lens 32 converges the first part or portion 42 of the parallel beams of light 36 reflected or returned by the reflector 40 to the output face 38 of the cylindrical lens 32. This converged first part or portion 42 is output by the cylindrical lens 32 as a converging light beam 30′ to the rotating reflector or mirror 10 which reflects the converged light beam 30′ impinging thereon as the output light beam 12 which is focused by the output lens 3-2 and provided or output to the output optical fiber 6.

If it is determined, either manually (e.g., empirically) or via the optional controller 22 from the values of electrical signals output by one or both of the optional photodiodes 16 and 18, that the output light beam 12 has too little brightness or intensity, the reflector 40 may be moved, in the direction of arrow 24, further into the path of the parallel beams of light 36, thereby allowing less of the parallel beams of light 36 to pass by the reflector 40 and more of the parallel beams of light 36 to be reflected by the reflector 40 back to the to the output face 38 of the cylindrical lens 32, thereby increasing the brightness or intensity of the output light beam 12.

On the other hand, if it is determined that the output light beam 12 has too much brightness or intensity, the reflector 40 may be moved, in the direction opposite arrow 24, further out of the path of the parallel beams of light 36, thereby allowing more of the parallel beams of light 36 to pass by the reflector 40 and less of the parallel beams of light 36 to be reflected by the reflector 40 back to the to the output face 38 of the cylindrical lens 32, thereby decreasing the brightness or intensity of the output light beam 12.

While not specifically shown, it is also envisioned that the reflector 40 may be moved completely into or out of the path of the parallel beams of light 36, thereby respectively completely reflecting the parallel beams of light 36 back to the output face 38 of the cylindrical lens 32, whereupon there is little or no attenuation of the input light beam 8, or completely allowing the parallel beams of light 36 to pass without reflection, whereupon there is complete attenuation of the input light beam 8 and no output light beam 12.

In an example, the rotating mirror 10 may be a Micro-Electro-Mechanical System (MEMS) mirror that may be configured and rotated at a speed as necessary and/or desired to reflect the input light beam 8 toward the cylindrical lens 32 while causing the input light beam 8 reflected thereby to diverge, e.g., in a cone shape, toward the input face 34 of the cylindrical lens 32. The rotating mirror 10 may also be configured and rotated at a speed as necessary and/or desired to reflect the converging light beam 30′ returned from the input face 34 of the cylindrical lens 32 as the output light beam 12 to the output lens 3-2 which focuses and provides or outputs the output light beam 12 to the output optical fiber 6. Where the input and output light beams 8 and 12 converge on the rotating mirror 10 in the figures is strictly for the purpose of illustration and is not to be construed in a limiting sense.

With reference to FIGS. 4A-4C, another example variable optical attenuator (VOA) 2 in accordance with the principles of the present disclosure may comprise a lens means 3 optically coupled to input and output optical fibers 4 and 6, e.g., via a dual pigtail (shown e.g. in FIG. 1A). In an example, the lens means 3 may comprise input and output lenses 3-1 and 3-2 (shown in phantom) optically coupled to the input and output optical fibers 4 and 6, respectively. The lens means 3 may comprise a lens array that includes the input and output lenses 3-1 and 3-2.

Disposed between the output face 38 of the cylindrical lens 32 and the reflector 40 is a moveable shutter or block 46 that may be moveable, at least partially, into and/or out of the path of the plurality of parallel beams of light 36. In an example, the shutter or block 46 may be positioned to block or obstruct a first part or portion 42 of the parallel beams of light 36 output by the output face 38 of the cylindrical lens 32 from reaching the reflector 40 and to pass a second part or portion 44 of the parallel beams of light 36 output by the output face 38 of the cylindrical lens 32 to the reflector 40. The reflector 40 reflects the second part or portion 44 of the parallel beams of light 36 back to the output face 38 of the cylindrical lens 32. In this example, the first part or portion 42 of the parallel beams of light 36 blocked or obstructed by the shutter or block 46 is absorbed thereby, whereupon little or none of the absorbed light is reflected, and is not used.

The cylindrical lens 32 converges the second part or portion 44 of the parallel beams of light 36 reflected or returned by the reflector 40 to the output face 38 of the cylindrical lens 32. This converged second part or portion 44 is output by the cylindrical lens 32 as a converging light beam 30′ to the rotating reflector or mirror 10 which reflects the converged light beam 30′ impinging thereon as the output light beam 12 which is focused by the output lens 3-2 and provided or output to the output optical fiber 6.

If it is determined, either manually (e.g., empirically) or via the optional controller 22 from the values of electrical signals output by one or both of the optional photodiodes 16 and 18, that the output light beam 12 has too little brightness or intensity, the shutter or block 46 may be moved, in a direction opposite arrow 24, further out of the path of the parallel beams of light 36. This movement allows more of the parallel beams of light 36 to pass by the shutter or block 46 for reflection by the reflector 40 back to the to the output face 38 of the cylindrical lens 32, thereby increasing the brightness or intensity of the output light beam 12.

On the other hand, if it is determined that the output light beam 12 has too much brightness or intensity, the shutter or block 46 may be moved, in the direction of arrow 24, further into the path of the parallel beams of light 36, thereby blocking more of the parallel beams of light 36 from reaching and being reflected by the reflector 40 back to the to the output face 38 of the cylindrical lens 32, thereby decreasing the brightness or intensity of the output light beam 12.

While not specifically shown, it is also envisioned that the shutter or block 46 may be moved completely into or out of the path of the parallel beams of light 36, thereby respectively adsorbing all of the parallel beams of light 36, whereupon there is complete or substantially complete attenuation of the input light beam 8 and no output light beam 12, or completely allowing the parallel beams of light 36 to pass to the reflector 40 without any adsorption by the shutter or block 46, whereupon there is little no attenuation of the input light beam 8.