KR20180116548A - Monostatic bidrectional focusing and collecting optics system - Google Patents

Abstract

The present invention relates to a monostatic bidirectional light-focusing and light-receiving optical system. The monostatic bidirectional light-focusing and light-receiving optical system includes: a light focusing module having a light focusing lens having a predetermined focal length or a light focusing optical system composed of two or more lenses; a light receiving module disposed on an optical axis of the light focusing module to process an optical signal received by the light focusing module to output the processed optical signal as an electric signal; a light source module for outputting an optical signal used as a transmission optical signal or detection light; a reflection mirror disposed on the optical axis of the light focusing module between the light focusing module and the light source module to reflect the optical signal outputted from the light source module to the light focusing module; and a control unit for detecting and processing data from the electric signal outputted from the light receiving module, and controlling the light source module to output the optical signal, wherein the optical signal reflected by the reflection mirror is collimated and emitted at a predetermined angle through the light focusing module, and the optical signal incident on the light focusing module is provided to the light receiving module. According to the monostatic bidirectional light-focusing and light-receiving optical system of the present invention, a single light focusing module is used to constitute an optical signal receiving unit and an optical signal transmitting unit, so that a configuration of the optical system becomes simple, and an overall size of equipment becomes small so as to be realized in a small size.

Description

[0001] Monostatic bidirectional focusing and collecting optics [

More specifically, the present invention relates to a bidirectional condensing and receiving optical system, and more particularly, to a condensing optical system for condensing and receiving light, which condenses light output from a light source onto a subject or transmits the light to a partner, And a monostatic bi-directional condensing and receiving optical system for condensing the light onto a receiving device.

Many optical devices require a bidirectional optical system that uses a light source to transmit light to the other party and collects the light transmitted from the other party and concentrates the light on the receiving device. For example, free space optical communications (FSO or FSO communications), also referred to as optical wireless communications, are two-way communications technologies that transmit or receive data using visible or infrared beams in free space Also referred to as optical wireless communications. This free space optical communication is the same as the optical fiber transmission theory, but differs in that it transmits the coded light through the space without going through the optical fiber.

1 is a schematic diagram illustrating an optical communication system implemented using a general free space optical system. 1, the free space optical system modulates visible light or an infrared beam emitted from a light source into data by a direct or indirect method and transmits the modulated light to an opponent using an optical system composed of a lens, A part of light or an infrared ray can be condensed on a photodetector by using an optical system for receiving and converted into an electric signal to recover data. Such bidirectional optical communication links are capable of communication within a few kilometers of the line of sight (LOS).

2 is a photograph of a general free space optical communication apparatus according to the prior art. As shown in FIG. 2, the conventional mono static bi-directional condensing and receiving optical system uses a lens for signal transmission and a lens for signal reception separately and uses them, so that the structure of the lens is complicated, the weight of the apparatus is heavy, There is a problem that the volume becomes very large, and the production cost also increases.

Another example is a vibrometer that measures the vibration of an object remotely. A focusing lens is used to collect the detection light emitted from the light source on the object, and a part of the scattered light that is scattered back from the object is collected using the optical system And it is analyzed by utilizing an interferometer or the like to measure the minute vibration of the object. In the related art, the light converging optical system and the receiving optical system are also used separately. In addition, there are various examples in which a focusing optical system and a light receiving optical system, such as a lidar device and a reflection type microscope, which are used as a remote distance measurement system, are separately constructed.

Korean Patent Publication No. 10-2004-0028975 Korean Patent Publication No. 10-2010-0023885 Korean Patent Publication No. 10-2008-0065251

An object of the present invention to solve the above-mentioned problems is to provide a monostatic optical system in which a light collecting part and a light receiving part are constructed using a single lens.

According to a first aspect of the present invention, there is provided a mono static bi-directional light collecting and receiving optical system including a light collecting lens having a predetermined focal length or a light converging optical system composed of two or more lenses; A light receiving module disposed on an optical axis of the condensing module and processing the optical signal received by the condensing module and outputting the processed optical signal as an electric signal; A light source module for outputting an optical signal for transmission or an optical signal used as detection light; A reflection mirror positioned on the optical axis of the condensing module and positioned between the condensing module and the light source module and reflecting the optical signal output from the light source module to the condensing module; And a control unit for detecting and processing data from the electric signal output from the light receiving module and controlling the light source module to output an optical signal, wherein the optical signal reflected by the reflecting mirror is transmitted to a dictionary The light signal is collimated and emitted at a predetermined angle, and the optical signal incident on the light condensing module is provided to the light receiving module.

In the mono static bi-directional light collecting and receiving optical system according to the first aspect of the present invention, the light receiving module is preferably composed of a photodetector and a clock and data restoring device.

In the mono static bi-directional light collecting and receiving optical system according to the first aspect of the present invention, the light source module is composed of a light source and a light source driving device, and the control unit controls the light source driving device of the light source module, So that the light source outputs the optical signal for transmission or the optical signal used as the detection light.

A mono static bi-directional light collecting and receiving optical system according to a second aspect of the present invention includes a light collecting module having a light converging lens having a predetermined focal length or a light converging optical system composed of two or more lenses; An optical fiber for receiving one end of which is disposed at a focal position of a lens constituting the condensing module and transmits an optical signal condensed by the lens; A light receiving module for recovering and outputting data from the optical signal transmitted through the receiving optical fiber; A light source module for outputting an optical signal for transmission or an optical signal used as detection light; A transmission optical fiber connected to the light source module at one end thereof for transmitting the optical signal output from the light source module; A reflecting mirror positioned on an optical axis of the condensing module and positioned between the condensing module and an end of the transmitting optical fiber and reflecting an optical signal output from an end of the transmitting optical fiber to the condensing module; And a controller for processing data provided from the light receiving module and controlling the light source module to output an optical signal; The optical signal of the light source module reflected by the reflection mirror is collimated and emitted at a predetermined angle through the condensing module and the optical signal inputted to the condensing module is provided to the light receiving module through the transmitting optical fiber.

In the mono static bi-directional condensing and receiving optical system according to the second aspect of the present invention, the light source module is composed of a light source and a light source driving device, and the control unit controls the light source driving device of the light source module, So that the light source outputs the optical signal for transmission or the optical signal used as the detection light.

In the mono static bi-directional condensing and receiving optical system according to the second aspect of the present invention, the numerical aperture (NA) of the light-converging lens constituting the condensing module is preferably larger than the NA of the light source.

In the mono static bi-directional condensing and receiving optical system according to the first and second aspects of the present invention, the reflecting surface of the reflecting mirror is arranged so that the central axis of the optical signal reflected by the reflecting mirror is moved along the optical axis of the condensing module .

The mono static bi-directional condensing and receiving optical system according to the present invention is configured to receive or transmit an optical signal using a single condensing module, thereby simplifying the configuration of the optical system, reducing the overall weight of the apparatus, . In addition, the monostatic bidirectional light collecting and receiving optical system according to the present invention can easily align the optical system and reduce the number of component parts compared with existing equipment, thereby reducing the manufacturing cost.

FIG. 1 is a schematic diagram for explaining an optical communication system implemented using general free space optical.
2 is a photograph of a general free space optical communication apparatus according to the prior art.
3 is a configuration diagram showing a mono static bi-directional condensing and receiving optical system according to the first embodiment of the present invention.
4 is a configuration diagram showing a mono static bi-directional condensing and receiving optical system according to a second embodiment of the present invention.
5 is a block diagram illustrating an optical communication system implemented using a mono static bi-directional condensing and receiving optical system according to the present invention.

The mono static bi-directional condensing and receiving optical system according to the present invention is characterized in that the light source module and the light receiving module are implemented using a single light collecting module.

Hereinafter, the configuration and operation of the mono static bi-directional condensing and receiving optical system according to the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

≪ Embodiment 1 >

Hereinafter, a mono static bi-directional condensing and receiving optical system according to a first preferred embodiment of the present invention will be described in detail with reference to FIG.

3 is a configuration diagram showing a mono static bi-directional condensing and receiving optical system according to the first embodiment of the present invention. 3, the monostatic bidirectional condensing and receiving optical system 3 according to the present embodiment includes a condensing module 300, a receiving optical fiber 320, a transmitting optical fiber 340, a reflecting mirror 360, A module 372, a light source module 374, and a control unit 370.

As shown in FIG. 3, the condensing module 300 may include a light-converging lens having a predetermined focal length, or may be a light-converging optical system formed of two or more lenses. The condensing module is used for both condensing and collimating, and a Fresnel lens or the like can be used. The focal length and the lens size of the lens constituting the condensing module may be set differently depending on the situation.

One end of the receiving optical fiber 320 is disposed at a focal point of the lens constituting the condensing module 300 and the other end is connected to an input end of the light receiving module 372 so that the optical signal condensed by the condensing module 300 To the light receiving module (372).

The light receiving module 372 restores data from the optical signal transmitted through the receiving optical fiber 320 and provides the data to the controller.

One end of the transmission optical fiber 340 is connected to the light source of the light source module and the other end is disposed to face the reflection surface of the reflection mirror to transmit the optical signal output from the light source to the reflection mirror.

The light source module 372 includes a light source connected to one end of the transmission optical fiber 340 and a light source driving device for driving the light source. The light source driving apparatus drives the light source under the control of the control unit, and it is generally preferable to use a light source having a communication wavelength of 1550 nm.

The reflection mirror 360 is positioned between the condensing module and one end of the transmission optical fiber 340 and is positioned on the optical axis of the lens constituting the condensing module, And reflects it to the condensing module 300. The reflecting mirror is preferably arranged so that the central axis of the optical signal reflected by the reflecting mirror travels along the optical axis of the condensing module. Thus, the optical signal reflected by the reflecting mirror is collimated through a condensing module at a predetermined angle and emitted to free space.

The control unit 370 processes the data received from the light receiving module and controls the light source driving unit of the light source module according to the data to be transmitted to drive the light source so that the light source outputs a transmission light signal or detection light do.

As described above, the mono static bi-directional light collecting and receiving optical system according to the present embodiment is advantageous in that the optical unit and the control unit can be separated from each other by using an optical fiber.

≪ Embodiment 2 >

Hereinafter, a monostatic bi-directional condensing and receiving optical system according to a second embodiment of the present invention will be described in detail with reference to FIG.

4 is a configuration diagram showing a mono static bi-directional condensing and receiving optical system according to a second embodiment of the present invention. 4, the mono static bi-directional condensing and receiving optical system 4 includes a condensing module 400, a light receiving module 410, a light source module 430, a reflecting mirror 460, and a controller 470 .

The condensing module 400 may be a light-converging lens having a predetermined focal length, or a light-converging optical system composed of two or more lenses and is used for condensing and collimating, and a Fresnel lens or the like may be used. The focal length and lens size of the condensing module may be set differently depending on the situation.

The light receiving module 410 is disposed at a focal point of the condensing module and restores the optical signal condensed by the condensing module to data. The light receiving module 410 is composed of a photodetector and a clock / data restoration device.

The light source module 430 includes a light source and a light source driving device. The light source provides an optical signal for transmission or a detection light. The optical module outputs a transmission optical signal or detection light corresponding to a transmission signal under the control of the transmission module of the control unit, and generally uses a light source having a communication wavelength of 1550 nm . The output surface of the light source is disposed so as to face the reflection surface of the reflection mirror, and outputs a transmission optical signal or detection light to the reflection mirror. The light source may be a laser diode.

The reflective mirror 460 is disposed on the optical axis of the condensing module, and is disposed between the condensing module and the light source, and the central axis of the optical signal reflected by the reflecting mirror is disposed to travel along the optical axis of the condensing module desirable. Thus, the optical signal reflected by the reflective mirror is collimated and emitted at a predetermined angle through the condensing module.

The control unit 470 includes a receiving module and a transmitting module. The receiving module processes the data received from the receiving module, and the transmitting module controls the light source driving device of the light source module, Or the detection light.

Hereinafter, a free space optical communication system using mono static bi-directional condensing and receiving optical systems according to the present invention will be described with reference to FIG. 5 is a block diagram illustrating an optical communication system implemented using a mono static bi-directional condensing and receiving optical system according to the present invention.

Referring to FIG. 5, the condensing modules of the first and second mono static bi-directional condensing and receiving optical systems according to the present invention are disposed facing each other to install the system. The first mono static bi-directional condensing and receiving optical system 50 collimates and emits the optical signal through a condensing module at a predetermined angle, and the second mono static bi-directional condensing and receiving optical system 52 uses the condensing module to convert the optical signal . When the second mono static bi-directional condensing and receiving optical system 52 collimates and outputs the optical signal through the condensing module at a predetermined angle, the first mono static bi-directional condensing and receiving optical system 50 transmits the optical signal .

In this case, since the separation distances of the first and second mono static bi-directional condensing and receiving optical systems are considerably long distances, even when the optical signal to be transmitted is emitted as a parallel beam, It can be incident on the area.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood that various changes and modifications may be made without departing from the spirit and scope of the invention. It is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or essential characteristics thereof.

The mono static bi-directional condensing and receiving optical system according to the present invention can be widely used in a free space optical communication system, a vibrometer for measuring the vibration of an object, and the like.

3, 4: Monostatic bidirectional condensing and receiving optical system
300, 400: condensing module
320: Receiving optical fiber
340: transmitting optical fiber
360, 460: reflective mirror
370, 470:
372, 410: Light receiving module
374, 430: Light source module

Claims (7)

A light converging module having a light converging lens having a predetermined focal length or a light converging optical system composed of two or more lenses;
A light receiving module disposed on an optical axis of the condensing module and processing the optical signal received by the condensing module and outputting the processed optical signal as an electric signal;
A light source module for outputting an optical signal for transmission or an optical signal used as detection light;
A reflection mirror positioned on the optical axis of the condensing module and positioned between the condensing module and the light source module and reflecting the optical signal output from the light source module to the condensing module; And
A control unit for detecting and processing data from the electric signal output from the light receiving module and controlling the light source module to output an optical signal;
Characterized in that the optical signal reflected by the reflecting mirror is collimated and emitted at a predetermined angle through the condensing module and the optical signal incident on the condensing module is provided as a light receiving module, Optical system. The monocular bi-directional condensing and receiving optical system according to claim 1, wherein the light receiving module comprises a photodetector and a clock and data recovery device. The apparatus of claim 1, wherein the light source module comprises a light source and a light source driving device,
Wherein the control unit controls the light source driving unit of the light source module so that the light source driving unit drives the light source so that the light source outputs an optical signal for transmission or detection light. And a light receiving optical system. A light converging module having a light converging lens having a predetermined focal length or a light converging optical system composed of two or more lenses;
An optical fiber for receiving one end of which is disposed at a focal position of a lens constituting the condensing module and transmits an optical signal condensed by the lens;
A light receiving module for recovering and outputting data from the optical signal transmitted through the receiving optical fiber;
A light source module for outputting an optical signal for transmission or an optical signal used as detection light;
A transmission optical fiber connected to the light source module at one end thereof for transmitting the optical signal output from the light source module;
A reflecting mirror positioned on an optical axis of the condensing module and positioned between the condensing module and an end of the transmitting optical fiber and reflecting an optical signal output from an end of the transmitting optical fiber to the condensing module; And
A control unit for processing data provided from the light receiving module and controlling the light source module to output an optical signal;
The optical signal of the light source module reflected by the reflecting mirror is collimated and emitted at a predetermined angle through the condensing module and the optical signal incident on the condensing module is provided to the light receiving module through the transmitting optical fiber A mono static bi-directional condensing and receiving optical system. The apparatus of claim 4, wherein the light source module comprises a light source and a light source driving device,
Wherein the control unit controls the light source driving unit of the light source module so that the light source driving unit drives the light source so that the light source outputs an optical signal for transmission or detection light. And a light receiving optical system. The monocular bi-directional condensing and receiving optical system according to claim 5, wherein the numerical aperture (NA) of the light-converging lens constituting the condensing module is larger than the NA of the light source. 7. A reflector according to any one of claims 1 to 6, characterized in that the reflecting surface of the reflecting mirror is arranged such that the central axis of the optical signal reflected by the reflecting mirror travels along the optical axis of the condensing module Bidirectional condensing and receiving optics.

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