Optical element with light-splitting function

An optical element includes a lens component and a filter. The lens component has a first plane, a second plane, a third plane, a fourth plane, a fifth plane, a first collimating unit formed on the first plane, a second collimating unit formed on the first plane, and a third collimating unit formed on the third plane. The first, second, third, fourth and fifth planes are disposed around and parallel to a reference axis. The third plane is formed with a groove defined by a sixth plane and a seventh plane which extend obliquely from the third plane and respectively opposite to the first and second planes. Each of the sixth and seventh planes extends in a direction that is parallel to the reference axis. The filter is disposed on the third plane for covering the groove.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Chinese Patent Application No. 201710413439.0, filed on Jun. 5, 2017.

FIELD

The disclosure relates to an optical element, and more particularly to an optical fiber adapter.

BACKGROUND

A first conventional optical element with light-splitting function is disclosed in U.S. Pat. No. 9,541,720, and a second conventional optical element with light-splitting function is disclosed in U.S. Pat. No. 9,588,308. The first and second conventional optical elements change an inclination angle of a light-splitting surface to increase the distance between a light source and a photo detector. However, when the distance between the light source and the photo detector is larger than a certain value, it may cause the following disadvantages:

1. The condensation of inclined light beams is low, so that the condensing area of the light beams is larger than the light-receiving area of the photo detector, thereby resulting in reduction of the light energy received by the photo detector. To solve this disadvantage, a larger photo sensor of the photo detector may be used, which may increase the manufacturing cost.

2. The light penetration rate of each light beam from a lens to air is decreased, so that the light coupling efficiency of the light beam into an optical fiber is low. When the inclination angle of the light-splitting surface is larger than the critical angle of total reflection, the light beam is totally reflected by the light-splitting surface, and the photo detector cannot fully receive any light signal.

Therefore, how to increase the distance between the light source and the photo detector without changing the inclination angle of the light-splitting surface becomes an important issue.

A third conventional optical element disclosed in U.S. Pat. No. 6,888,9888 also includes a photo-detecting structure. However, two photo detectors of the third conventional optical element are disposed between a light source and a receiving end of an optical fiber, such that the distance between the light source and the receiving end of the optical fiber is long. A light beam emitted from the light source needs to be reflected by a reflection surface to the receiving end. Since a receiving distance deviation of the receiving end caused by an inclination angle deviation of the reflection surface is proportional to the distance between the light source and the receiving end, the inclination angle deviation of the reflection surface may cause serious receiving distance deviation. The diameter of a receiving end of a conventional optical fiber is only 50-62 micro-millimeters, and when the light beam deviates from the receiving end of the conventional optical fiber, the receiving end of the conventional optical fiber may receive low optical signal or may not receive optical signal, and thereby leading to a failed communication.

SUMMARY

Therefore, the object of the disclosure is to provide an optical element that can alleviate at least one of the drawbacks of the prior art.

According to the disclosure, the optical element includes a lens component and a filter. The lens component has a first plane, a second plane, a third plane, a fourth plane, a fifth plane, a first collimating unit formed on the first plane, a second collimating unit formed on the first plane, and a third collimating unit formed on the second plane. The first, second, third, fourth and fifth planes are disposed around and parallel to a reference axis. The third plane is formed with a groove defined by a sixth plane and a seventh plane which extend obliquely from the third plane and respectively opposite to the first and second planes. Each of the sixth and seventh planes extends in a direction that is parallel to the reference axis. The filter is disposed on the third plane for covering the groove, and has a first side surface facing the sixth and seventh planes, and a second side surface opposite to the first side surface, and facing the fourth plane. When light beams incident from the first collimating unit propagate within the lens component along a first optical path to enter, by refraction through the sixth plane, and propagate within the groove to reach the first side surface, followed by being reflected by the first side surface to reach the seventh plane, a part of the light beams enters, by refraction through the seventh plane, and propagates within the lens component along a second optical path to exit the lens component through the third collimating unit, and the remaining part of the light beams is reflected by the seventh plane to propagate within the groove, to thereby enter and propagate within the filter, by refraction through the first side surface, and subsequently exit the filter, by refraction through the second side surface along a monitoring optical path, followed by entering and propagating within the lens component, by refraction through the fourth plane, to reach the fifth plane to thereby be reflected by the fifth plane to exit the lens component through the second collimating unit.

DETAILED DESCRIPTION

Referring toFIGS. 1 and 2, the embodiment of an optical element with light-splitting function includes a lens component1and a filter2.

The lens component1is made of one of glass and plastic. In this embodiment, the lens component1is made of plastic, which may be varied in other embodiments. The lens component1has a first plane10, a second plane11, a third plane12, a fourth plane13and a fifth plane14. The first, second, third, fourth and fifth planes10,11,12,13,14are disposed around and parallel to a reference axis (L). In this embodiment, the first plane10is perpendicular to the second plane11, and such configuration may be varied in other embodiments. In this embodiment, an angle defined between the first plane10and the fifth plane14is 45 degrees, and may be varied in other embodiments. The third plane12is formed with a groove121defined by a sixth plane15and a seventh plane16which extend obliquely from the third plane12and respectively opposite to the first and second planes10,11. Each of the sixth and seventh planes15,16extends in a direction that is parallel to the reference axis (L). The lens component1further has a first collimating unit17and a second collimating unit18that are formed on the first plane10, and a third collimating unit19formed on the second plane11. The first collimating unit17has a plurality of rounded first protrusions171arranged in a width direction which is parallel to the reference axis (L). The second collimating unit18has a plurality of rounded second protrusions181arranged in the width direction. The third collimating unit19has a plurality of rounded third protrusions191arranged in the width direction. It should be noted that, the first protrusions171may be arranged in the width direction in one row (seeFIG. 1), and may also be arranged in the width direction in two juxtaposed rows (seeFIG. 3), the second protrusions181may be arranged in the width direction in one row (seeFIG. 1), and may also be arranged in the width direction in two juxtaposed rows (seeFIG. 3), and the third protrusions191may be arranged in the width direction in one row (seeFIG. 1), and may also be arranged in the width direction in two juxtaposed rows (seeFIG. 3).

The filter2is made of one of glass and plastic. In this embodiment, the filter2is made of glass, which may be varied in other embodiments. The filter2is disposed on the third plane12for covering the groove121, and has a first side surface21facing the sixth and seventh planes15,16, and a second side surface22opposite to the first side surface21, and facing the fourth plane13. The first side surface21is formed with a plated film23. It should be noted that, when an incident angle of a light beam is larger than 40 degrees, the plated film23has a reflective rate larger than 90%, and when an incident angle of the light beam is smaller than 30 degrees, the plated film23has a light transmittance larger than 90%.

When the disclosure is applied to be an optical fiber adapter, the first collimating unit17is aligned with a light source unit3, and the first protrusions171of the first collimating unit17are respectively aligned with a plurality of light sources32of the light source unit3, the second collimating unit18is aligned with a photo detector unit5, and the second protrusions181of the second collimating unit18are respectively aligned with a plurality of photo detectors51of the photo detector unit5, and the third collimating unit19is aligned with an optical fiber unit4, and the third protrusions191of the third collimating unit19are respectively aligned with a plurality of receiving ends41of optical fibers42of the optical fiber unit4.

When a light beam31of each of the light sources32incident through a corresponding one of the first protrusions171propagates within the lens component1along a first optical path (I) to enter, by refraction through the sixth plane15, and propagate within the groove121to reach the first side surface21, followed by being reflected by the first side surface21to reach the seventh plane16, a first part of the light beam31enters, by refraction through the seventh plane16, and propagates within the lens component1along a second optical path (II) to exit the lens component1to reach a corresponding one of the receiving ends41of the optical fibers42through a corresponding one of the third protrusions191, and the remaining or second part of the light beam31is reflected by the seventh plane16to propagate within the groove121, to thereby enter and propagate within the filter2, by refraction through the first side surface21, and subsequently exit the filter2, by refraction through the second side surface22along a monitoring optical path (V), followed by entering and propagating within the lens component1, by refraction through the fourth plane13, to reach the fifth plane14to thereby be reflected by the fifth plane14to exit the lens component1to reach a corresponding one of the photo detectors51through a corresponding one of the second protrusions181.

With such disposition, the distance between the light source unit3and the photo detector unit5is increased without affecting the light energy and the detecting sensitivity. In this embodiment, the second part of each of the light beams31of the light sources32is totally reflected by the fifth plane14, such that loss of energy is decreased. It should be noted that, the reflection on the fifth plane14may not be a total reflection in other embodiments.

Since the plated film23has a reflective rate larger than 90% when the incident angle of each of the light beam31is larger than 40 degrees. In this embodiment, the first plane10is parallel to the sixth plane15, and such configuration may be varied in other embodiments. In this embodiment, an angle defined between the sixth plane15of the lens component1and the first side surface21of the filter2is 45 degrees, such that the incident angle of the first part of each of the light beams31along the first optical path (I) to the plated film23is 45 degrees, and most of the first part of each of the light beams31can be reflected to propagate along the second optical path (II). The angle defined between the sixth plane15and the first side surface21may be varied in other embodiments. In this embodiment, an angle defined between the sixth plane15and the seventh plane16is slightly larger than 90 degrees and smaller than 135 degrees. In such manner, the incident angle of the second part of the light beams31relative to the plated film23along the monitoring optical path (V) is small, and most of the second part of the light beams31can thereby pass through the plated film23.

The disclosure can guide a part of the light beams31into the photo detector unit5for monitoring the light energy. Such closed-loop feedback function can increase the stability of the light signals to satisfy the requirement of high bandwidth signal transmission.

In addition, when a laser light source is used as the light source unit3, it is required to be maintained in a certain working situation so as to have a long service life and a high luminous efficiency. However, laser light signal usually has excess energy so that the optical fiber unit4might receive the laser light signal with the energy higher than the optical communication standard. To solve this problem, the material and the structure of the plated film23can be varied for decreasing the energy of the laser light signal.

Moreover, since a light beam needs to be reflected by a surface into an optical fiber, and since a receiving distance deviation of the optical fiber is proportional to the distance between a light source and a receiving end of the optical fiber, when the receiving distance deviation is large, only one part of light signal is received by the receiving end, thereby resulting in a failed communication. In this embodiment, since the optical fiber unit4and the photo detector unit5are respectively disposed at two opposite sides of the light source unit3, a distance (d) between the light source unit3and the optical fiber unit4is short, so that a receiving distance deviation is small and a tolerance range of an inclination angle deviation of the first side surface21is greatly increased.

In conclusion, with the abovementioned configuration, the optical element of the disclosure has the following advantages:

1. Since the light beams31are transmitted into the plated film23at different incident angles, they can be both reflected and refracted for transmitting light signals into the optical fiber unit4and the photo detector unit5. Furthermore, with the dispositions of the fourth plane13and the fifth plane14, the distance between the light source unit3and the photo detector unit5is increased.

2. By changing the material and the structure of the plated film23, the plated film23not only has high reflective rate with respect to the light beams31of large incident angles and high light transmittance with respect to the light beams31of small incident angles, but also can adjust the energy of the light signal for ensuring that the receiving ends41of the optical fiber unit4can receive the light signals within the optical communication standard.

3. By decreasing the distance (d) between the light source unit3and the optical fiber unit4, the receiving ends41can further fully receive the light signals.