Apparatus and method for highly-efficiently tuning the wavelength of light using a collimating module including an axicon lens

Abstract

The present invention provides a light source device and method that utilizes a parallel optical module including an axicon lens to efficiently collect diverging light, collimate it, and adjust the wavelength of the desired light to pass through. A tunable wavelength light source device according to one embodiment of the present invention includes a diffused light source that irradiates diffused light, a parallel light module that collimates the light irradiated from the diffused light source, the parallel light module including an axicon lens, an angle-adjustable bandpass filter module that passes light that has passed through the parallel light module and selects a specific wavelength of the light, and a mixing module that corrects an error in wavelength that is determined by the angle of incidence of light that passes through the angle-adjustable bandpass filter module.

Description

[Technical Field]

[0001] The present invention relates to a light source device and method that utilizes a parallel optical module including an axicon lens to collect diverging light with high efficiency, collimate it, and adjust the wavelength of the desired light to pass through. [Background technology]

[0002] Optical imaging techniques or inspection equipment aim to obtain specific information through changes that occur after irradiating a specific area with light, or by irradiating a specific wavelength of light depending on the object being observed and analyzing the phenomenon that occurs afterwards.

[0003] That is, in the technical field to which the present invention pertains, it is required to irradiate light having a rectilinear property, and in particular, light of a specific wavelength suitable for the information to be obtained from an object is irradiated in a rectilinear manner, and then the information is obtained by analyzing the light by checking changes in transmitted or reflected light or checking other light emitted.

[0004] In this case, when selecting light for imaging or analysis, a laser can be used, which has a small divergence angle (the angle at which light spreads as it travels) and excellent linearity. However, because lasers have a single wavelength, multiple lasers with specific wavelengths within the visible light range of 400 to 700 nm must be provided, which is costly and inefficient. This problem becomes more severe as the desired wavelength range widens. To solve this problem, wavelength-tunable lasers using dyes or nonlinear phenomena can be used. However, wavelength-tunable lasers have disadvantages such as being very expensive and difficult to maintain and repair, and wavelength changes.

[0005] On the other hand, relatively inexpensive light sources such as general lamps and light emitting diodes (LEDs) can be used, but since they have a wide range of wavelengths, it requires additional effort and cost to obtain a specific wavelength, and since the light emitting area is relatively large and the divergence angle is large, it is difficult to obtain linearity.

[0006] More specifically, in the process of making the light emitted from a general lamp and an LED rectilinear, most of the light emitted from the light source is lost, and only a portion of the light emitted from a specific direction can be used, resulting in significantly lower output and lower efficiency. Specifically, referring to Figure 1, unlike the case of Figure 1(a) where the light is rectilinear, in the case of Figure 1(b) where the light is diffused in the air, for example, when the light source is a general lamp or an LED, aberration occurs due to the angle at which the light spreads from multiple points, making it difficult to convert the light into parallel light (i.e., collimate), resulting in lower efficiency.

[0007] That is, the light used in a microscope or industrial inspection equipment must be collimated. In this case, if the light source is a general lamp or LED, the amount of light is significantly lost during the collimation process, which is inefficient.

[0008] Therefore, in the microscope industry, only a portion of the light source is used through a method called a pinhole, as shown in Figure 2, but this method also has the disadvantage of low efficiency. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention aims to provide a highly efficient tunable wavelength light source device and method that can efficiently collect and collimate light emitted from a general lamp or LED, which has the advantage of being inexpensive but can cause a large loss of light intensity, while at the same time selecting a desired wavelength of light. [Means for solving the problem]

[0010] In order to solve the above-mentioned technical problems, a tunable wavelength light source device according to one embodiment of the present invention includes: a diffused light source that irradiates diffused light; a parallel light module that collimates the light irradiated from the diffused light source, the parallel light module including an axicon lens; an angle-adjustable bandpass filter module that passes light that has passed through the parallel light module to select a specific wavelength of the light; and a mixing module that corrects a spatial error of a wavelength that is determined by the angle of incidence of light that passes through the angle-adjustable bandpass filter module.

[0011] The angle-adjustable bandpass filter module is a circular plate and includes a plurality of angle-adjustable bandpass filters that are arranged in a circular pattern on the edge of the angle-adjustable bandpass filter module. Each of the angle-adjustable bandpass filters selects a different wavelength band of light that passes through the corresponding filter. To select a specific wavelength band of light, one of the angle-adjustable bandpass filters can be selected by rotating the angle-adjustable bandpass filter module.

[0012] Each of the plurality of angle-adjustable bandpass filters is rotated so that the angle of incidence of light relative to the corresponding filter is adjusted, and different wavelengths of light passing through the filter are selected depending on the angle of incidence. When light passes through a selected angle-adjustable bandpass filter from the plurality of angle-adjustable bandpass filters at an angle of incidence specified by rotating the angle-adjustable bandpass filter, a specific wavelength within a selected wavelength band of light can be selected.

[0013] The tunable wavelength light source device of the present invention further includes another angle-adjustable bandpass filter module, and by rotating the another angle-adjustable bandpass filter module and the angle-adjustable bandpass filter of the another angle-adjustable bandpass filter module, the bandwidth of a band having the specific wavelength within the selected wavelength band as its center wavelength can be adjusted.

[0014] The angle of incidence of light on the angle-adjusted bandpass filter may be greater than or equal to 0° and less than 90°.

[0015] The diffuse light source can be a light emitting diode (LED) or a lamp.

[0016] The mixing module can be an optical fiber, a liquid crystal light guide, or a rod lens.

[0017] According to another embodiment of the present invention, a method for providing a tunable wavelength light source includes the steps of: irradiating diffusing light with a diffuse light source; collimating the light emitted from the diffuse light source with a parallel light module, where the parallel light module includes an axicon lens; selecting a specific wavelength of light by passing the light that has passed through the parallel light module with an angle-adjustable band-pass filter module; and correcting, with a mixing module, an error in wavelength determined by the angle of incidence of the light that passes through the angle-adjustable band-pass filter module.

[0018] The method for providing a tunable wavelength light source of the present invention may further include a step of rotating the angle-adjustable bandpass filter module, wherein the angle-adjustable bandpass filter module is a circular plate and includes a plurality of angle-adjustable bandpass filters, the plurality of angle-adjustable bandpass filters being arranged in a circular pattern on an edge of the angle-adjustable bandpass filter module, each of the plurality of angle-adjustable bandpass filters selecting a different wavelength band of light to pass through the corresponding filter, wherein rotating the angle-adjustable bandpass filter module selects one of the plurality of angle-adjustable bandpass filters to select a specific wavelength band of light.

[0019] The method for providing a tunable wavelength light source of the present invention may further include a step of rotating angle-adjustable bandpass filters, wherein each of the plurality of angle-adjustable bandpass filters is rotated so that an incident angle of light to the corresponding filter is adjusted, and different wavelengths of light passing through the filter are selected depending on the incident angle, and a specific wavelength within a selected wavelength band of light is selected by light passing through a selected angle-adjustable bandpass filter from the plurality of angle-adjustable bandpass filters at an incident angle specified by rotating the angle-adjustable bandpass filter.

[0020] The method for providing a tunable wavelength light source of the present invention may further include a step of rotating another angle-adjustable bandpass filter module, in which case, by rotating the another angle-adjustable bandpass filter module and the angle-adjustable bandpass filter of the another angle-adjustable bandpass filter module, the bandwidth of a band having the specific wavelength within the selected wavelength band as its center wavelength can be adjusted.

[0021] The angle of incidence of light on the angle-adjusted bandpass filter may be greater than or equal to 0° and less than 90°.

[0022] In the step of irradiating light, the diffuse light source may be a light emitting diode (LED) or a lamp.

[0023] In the step of equalizing the error due to the incident angle of the light, the mixing module may be an optical fiber, a liquid crystal light guide, or a rod lens. [Effects of the Invention]

[0024] According to the present invention as described above, a collimated tunable wavelength light source can be obtained at low cost and with high efficiency by collimating diverging light with a parallel light module including an axicon lens, selecting the wavelength of the collimated light with an angle-adjustable bandpass filter module, and uniformly correcting wavelength errors determined by the angle of incidence of light that has passed through the angle-adjustable bandpass filter module with a mixing module. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1(a) shows the progression of light having a straight line, and FIG. 1(b) shows the progression of diffused light. [Figure 2] FIG. 2 is a diagram showing the structure inside a confocal microscope including a pinhole. [Figure 3] FIG. 3 is a diagram showing an embodiment of a light source device according to the present invention. [Figure 4] FIG. 4 is a diagram showing an example of a light path in a light source device according to the present invention. [Figure 5] FIG. 5 shows the results of a simulation in which diverging light is passed through a parallel optical module that does not include an axicon lens. [Figure 6] FIG. 6 shows the results of a simulation in which diverging light is passed through a parallel optical module including an axicon lens. [Figure 7]FIG. 7 is a diagram showing an embodiment of the angle-adjustable bandpass filter of the present invention. [Figure 8] FIG. 8 is a diagram showing an embodiment of an angle-adjustable bandpass filter module according to the present invention. [Figure 9] FIG. 9(a) shows an example of the rotational movement of an angle-adjustable bandpass filter module of the present invention, and FIG. 9(b) is a diagram showing an example of the rotational movement of an angle-adjustable bandpass filter of the present invention. [Figure 10] FIG. 10 shows another embodiment including an angle-adjustable bandpass filter. [Figure 11] FIG. 11 is a diagram showing an embodiment of a mixing module of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The advantages and features of the present invention, as well as methods for achieving them, will become apparent from the following detailed description of the embodiments in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, and may be embodied in various different forms. These embodiments are provided solely to ensure that the disclosure of the present invention is complete and to fully convey the scope of the invention to those skilled in the art. The present invention is defined only by the scope of the claims. The same reference numerals refer to the same elements throughout the specification.

[0027] Unless otherwise defined, all terms (including technical and scientific terms) used herein are to be used in the sense that they can be commonly understood by those having ordinary skill in the art to which the present invention belongs. Furthermore, commonly used and predefined terms are not to be interpreted ideally or excessively unless they are clearly and specifically defined.

[0028] The terms used in this specification are intended to describe the embodiments and are not intended to limit the present invention. In this specification, the singular form includes the plural form unless otherwise specified in the text. As used in the specification, "comprises" and / or "comprises" does not exclude the presence or addition of one or more other components other than the components mentioned.

[0029] Hereinafter, a light source device and method for efficiently adjusting the wavelength of light using a parallel optical module including an axicon lens according to an embodiment of the present invention will be described with reference to the accompanying drawings.

[0030] Referring to FIG. 3, the light source device of the present invention includes a diffused light source (1), a parallel light module (2) including an axicon lens (21), an angle-adjustable bandpass filter module (3), and a mixing module (4).

[0031] More specifically, referring to FIG. 4, in the tunable wavelength light source device of the present invention, light is irradiated from a diffused light source (1) and diffused, and passes through a parallel light module (2) including an axicon lens (21) to efficiently collect and collimate the light. Thereafter, the light passes through an angle-adjustable bandpass filter module (3) to select a specific wavelength, and then passes through a mixing module (4) to adjust for any error in the angle of incidence of the light on the angle-adjustable bandpass filter (3).

[0032] The collimating optical module 2 of the present invention includes an axicon lens 21. The collimating optical module 2 of the present invention may further include at least one lens 22 in addition to the axicon lens 21. For example, light emitted from a multi-focus light source and traveling from multiple focal points may be effectively collected by the axicon lens 21, and the collected light may be collimated by passing through the lens 22. The lens 22 further included in the collimating optical module 2 of the present invention may be, but is not limited to, a convex lens, as long as it can collect and / or collimate light. The collimating optical module 2 of the present invention may be, for example, an axicon lens 21, two convex lenses that perform the function of collimation, and one focusing lens composed of convex lenses. Specifically, the axicon lens (21) narrows the divergence angle by collecting light that has a large divergence angle and is scattered in the air, the two convex lenses collect the light to the maximum extent and then collimate it, and the focusing lens collects the light to the maximum extent and then emits it, thereby outputting light with high energy density.

[0033] The light source of the present invention refers to a diffuse light source 1. Specifically, the diffuse light source 1 refers to any light source that emits diffused light, and the diffused light may have a single or multiple focal points. For example, the diffuse light source 1 may be a general lamp or a light-emitting diode (LED), and the light emitted from the diffuse light source 1 may travel in the form shown in Figure 1(b).

[0034] The diffused light source (1) has the advantage of being inexpensive, but has the disadvantage that it is difficult to collimate the light because aberration occurs depending on the angle at which the light spreads from multiple points, and even if a diffused light source is collimated, there is a large loss of power.

[0035] Therefore, the inventors of the present application have devised a configuration in which light emitted from a diffused light source is passed through a parallel optical module including an axicon lens in order to reduce costs by using a diffused light source and at the same time obtain collimated light with little loss of power.

[0036] Generally, in the technical field to which the present invention pertains, axicon lenses are used in conjunction with laser beams that have a linear propagation characteristic. That is, since axicon lenses are generally used in conjunction with laser beams to produce circular light, it is uncommon to use an axicon lens in conjunction with a diffused light source in the technical field to which the present invention pertains. However, the inventors of the present invention have adopted a configuration that combines a diffused light source with an axicon lens, which is uncommon in the technical field to which the present invention pertains, and have found that light emitted from the diffused light source can be efficiently collected by passing through the axicon lens.

[0037] Specifically, the light intensities calculated through simulation when light irradiated from a diffused light source passes through a parallel optical module without an axicon lens and a parallel optical module with an axicon lens are shown in Figures 5 and 6. For reference, the inventors performed the simulations using Ray Optics Simulation.

[0038] 5, the parallel light module in Fig. 5 does not include an axicon lens. In this case, a significant portion of the light emitted from the diffuse light source cannot pass through the parallel light module, and only a portion of the light emitted from the diffuse light source is collected and collimated by passing through the parallel light module, and it was confirmed that the output light energy flow was 148 cd (candela).

[0039] In contrast, referring to Fig. 6, it can be seen that the collimating optical module in Fig. 6 includes an axicon lens. In this case, only a portion of the light irradiated from the diffused light source cannot pass through the axicon lens, and most of the light irradiated from the diffused light source is effectively collected by passing through the axicon lens, and then collected and collimated by passing through the lens included in the collimating optical module, thereby confirming that the output light energy flow is 197 cd.

[0040] That is, through the above simulation results, it was confirmed that the amount of output light is increased by about 1.33 times when using a parallel optical module including an axicon lens as shown in FIG. 6 compared to when using a parallel optical module without an axicon lens as shown in FIG. 5.

[0041] In other words, by incorporating an axicon lens, which is not normally used for diffuse light sources, into the parallel light module, the inventors of the present application were able to efficiently collect and collimate the light emitted from the diffuse light source, thereby reducing costs and overcoming the power limitations of diffuse light sources.

[0042] The angle-tunable bandpass filter module of the present invention serves to select the wavelength band of light passing through the angle-tunable bandpass filter module. For example, when light passes through the angle-tunable bandpass filter module, the wavelength of the light can be selected to be a wavelength in the visible light range of 400 to 700 nm. In one embodiment, the wavelength of the light passing through the angle-tunable bandpass filter module can be selected to be a wavelength band having a narrow bandwidth of approximately 2 nm centered on 561 nm. In another embodiment, the wavelength of the light passing through the angle-tunable bandpass filter module can be selected to be a wavelength band having a bandwidth of approximately 10 to 15 nm centered on 561 nm. In still another embodiment, the wavelength of the light passing through the angle-tunable bandpass filter module can be selected to be a wavelength band having a bandwidth of approximately 2 nm or a bandwidth of approximately 10 to 15 nm centered on 512 nm.

[0043] In the present invention, light passing through a parallel light module including an axicon lens can pass through an angle-adjustable bandpass filter module, and light having a specific wavelength selected by passing through the angle-adjustable bandpass filter module can be incident on a mixing module.

[0044] Furthermore, the angle-adjustable bandpass filter module 3 of the present invention can include an angle-adjustable bandpass filter 30 as a bandpass filter. The angle-adjustable bandpass filter 30 of the present invention can be rotated. For example, the angle-adjustable bandpass filter 30 of the present invention can be rotated by a motor, but this is not limiting, and configurations other than a motor are also possible as long as the angle-adjustable bandpass filter 30 can be rotated.

[0045] Furthermore, the angle-adjustable bandpass filter 30 of the present invention can be rotated to variously set the angle at which light enters the angle-adjustable bandpass filter 30, i.e., the angle of incidence (AOI) of light relative to the filter. The AOI can be greater than or equal to 0° and less than 90°, and preferably the AOI can be 0° (normal incidence), 30°, 45°, or 60°.

[0046] Furthermore, in the present invention, the wavelength of light passing through the angle-adjustable bandpass filter 30 can be selected depending on the angle of incidence (AOI). Specifically, as the angle of incidence (AOI) gradually increases from 0°, the wavelength of light passing through the angle-adjustable bandpass filter 30 and output tends to become shorter. Mathematically, when the angle of incidence (AOI) is θ and n eff is the effective refractive index, which is specified by the filter configuration and two orthogonal states of polarization, when

[0047]

number

[0048] is as follows:

[0049]

number

[0050] 7, when the collimated light passing through the parallel light module of the present invention passes through the angle-adjustable bandpass filter (30) at an angle of incidence (AOI) of 0°, the wavelength of the light can be set to have the A wavelength band. Also, when the collimated light passing through the parallel light module of the present invention passes through the angle-adjustable bandpass filter (30) at an angle of incidence (AOI) of 60°, the wavelength of the light can be set to have the B wavelength band. For example, when the angle of incidence (AOI) is 0°, the center of the wavelength band of the selected light can be approximately 561 nm, i.e., the center of the A wavelength band can be approximately 561 nm. Also, when the angle of incidence (AOI) is 60°, the center of the wavelength band of the selected light can be approximately 512 nm, i.e., the center of the B wavelength band can be approximately 512 nm.

[0051] The angle-adjustable bandpass filter module 3 of the present invention may be a circular plate. Specifically, it may be a circular plate having a predetermined thickness, and its center may be connected to a motor. The angle-adjustable bandpass filter module 3 of the present invention may include a plurality of angle-adjustable bandpass filters 30. The plurality of angle-adjustable bandpass filters 30 may be arranged in a circular pattern around the edge of the angle-adjustable bandpass filter module 3. For example, the angle-adjustable bandpass filter module 3 of the present invention may have a shape as shown in FIG. 8. Furthermore, in the present invention, one of the plurality of angle-adjustable bandpass filters 30 may be selected by automatically or manually rotating the angle-adjustable bandpass filter module 3 using a motor.

[0052] The device including the light source device of the present invention can have any form as long as it includes a diffused light source, a parallel light module including an axicon lens, an angle-adjustable bandpass filter module, and a mixing module, thereby efficiently collecting and collimating the light emitted from the diffused light source.

[0053] In the angle adjustable bandpass filter module (3) of the present invention, there are two kinds of rotational movements.

[0054] 9(a), in the present invention, the angle-adjustable bandpass filter module 3 can be rotated to select one of the plurality of angle-adjustable bandpass filters 30 formed on the edge of the angle-adjustable bandpass filter module 3. In this case, one of the plurality of angle-adjustable bandpass filters 30 can be selected by a motor and / or a control device connected to the angle-adjustable bandpass filter module 3. In this way, in the present invention, a specific wavelength range of light passing through the angle-adjustable bandpass filter module can be selected. For example, a wavelength range including a wavelength of 532 nm can be selected.

[0055] The present invention has a configuration in which a plurality of angle-adjustable bandpass filters (30) are provided, one of which can be selected, thereby achieving the effect of enabling a variety of wavelength bands of light to be selected according to the object to be inspected with a simple configuration.

[0056] Next, as previously mentioned, the angle-adjustable bandpass filter 30 included in the angle-adjustable bandpass filter module 3 can also be rotated. By rotating the angle-adjustable bandpass filter 30, the angle of incidence (AOI) of light on the filter 30 can be changed, thereby allowing the wavelength of light passing through the filter 30 to be selected as desired. For example, within the wavelength range including the previously selected wavelength of 532 nm, a wavelength band having a center wavelength of 532 nm can be selected.

[0057] That is, the angle-adjustable bandpass filter module (3) of the present invention has two types of rotational motion, and by adjusting these two types of rotational motion, it is possible to arbitrarily select a specific wavelength within a desired wavelength range within a wide wavelength range. In other words, the angle-adjustable bandpass filter module and the configuration for rotating it with two types of rotational motion in the present invention widen the range of selectable wavelengths, and as a result, it is not necessary to provide multiple light sources (e.g., lasers) with a single wavelength, and it is possible to output a collimated light source with an arbitrary wavelength using only a diffuse light source with a wide range of wavelengths.

[0058] Furthermore, the tunable wavelength light source device of the present invention may further include another angle-adjustable bandpass filter module. For example, the tunable wavelength light source device of the present invention may include two angle-adjustable bandpass filter modules. In this case, by rotating one angle-adjustable bandpass filter module and the angle-adjustable bandpass filter of the one angle-adjustable bandpass filter module, a specific wavelength within a specific wavelength region can be selected, as previously described. In this case, by rotating the other angle-adjustable bandpass filter module and the angle-adjustable bandpass filter of the other angle-adjustable bandpass filter module, the bandwidth of a wavelength band having a specific wavelength within the selected specific wavelength region as its center wavelength can be adjusted. For example, the bandwidth of a wavelength band having a previously selected center wavelength of 532 nm can be adjusted.

[0059] Therefore, the present invention has the advantage of being able to freely adjust a desired specific wavelength region, a wavelength band within the specific wavelength region, and its bandwidth by using one or more angle-adjustable bandpass filter modules and one or more angle-adjustable bandpass filters included in the angle-adjustable bandpass filter modules.

[0060] On the other hand, even if the light emitted from the diffuse light source of the present invention passes through the parallel light module, the light may not be completely collimated. Specifically, referring to Fig. 11, even after the light emitted from the diffuse light source passes through the parallel light module, the light rays may not be incident parallel to the angle-adjustable bandpass filter 30. In this case, the angles of incidence (AOI) of the respective light rays on the angle-adjustable bandpass filter 30 are spatially different, and therefore, the wavelengths selected for the respective light rays passing through the angle-adjustable bandpass filter 30 are different.

[0061] To solve this problem, the present invention may include a mixing module, which can spatially correct the wavelength selected to be different from the desired wavelength when light that has passed through the parallel light module but is not collimated passes through the angle-adjustable bandpass filter 30.

[0062] 11, the wavelengths of the light beams passing through the angle-adjustable bandpass filter 30 may be selected as wavelength A, wavelength B, and wavelength C, respectively. In this case, the mixing module of the present invention may function to correct wavelength A, wavelength B, and wavelength C, for example. More specifically, if the light beams passing through the parallel light module are collimated and incident parallel to the angle-adjustable bandpass filter 30 at the same angle of incidence (AOI), it can be assumed that light having wavelength B is output from the angle-adjustable bandpass filter 30. Furthermore, if the light beams passing through the parallel light module are not incident parallel to the angle-adjustable bandpass filter 30 at the same angle of incidence (AOI), but pass through the angle-adjustable bandpass filter 30 at different angles of incidence (AOI), light having wavelength A, wavelength B, and wavelength C may be output from the angle-adjustable bandpass filter 30. In this case, the mixing module 4 of the present invention functions to correct the light having wavelengths A, B, and C output from the angle-adjustable bandpass filter 30 so that it has wavelength B. In other words, the mixing module 4 of the present invention functions to output the same wavelength regardless of the position through which the light passes within the mixing module 4.

[0063] The mixing module of the present invention may be an optical fiber, a liquid crystal light guide, or a rod lens, but is not limited thereto, and various other products may be applied.

[0064] Next, a method for providing a tunable wavelength light source of the present invention will be described. The method for providing a light source of the present invention relates to a method for providing a tunable wavelength light source by using the light source device of the present invention.

[0065] Specifically, the method for providing a tunable wavelength light source of the present invention includes the steps of: irradiating diffused light from a diffuse light source; collimating the light emitted from the diffuse light source with a parallel light module, where the parallel light module includes an axicon lens; selecting a specific wavelength of light by passing the light that has passed through the parallel light module with an angle-adjustable bandpass filter module; and correcting a wavelength error determined by the angle of incidence of the light that passes through the angle-adjustable bandpass filter module with a mixing module. In this case, in the step of collimating the light emitted from the diffuse light source, the parallel light module includes an axicon lens.

[0066] The step of selecting a specific wavelength of light of the present invention may further include a step of rotating the angle-adjustable bandpass filter module, wherein the angle-adjustable bandpass filter module is a circular plate and includes a plurality of angle-adjustable bandpass filters that are circularly arranged on an edge of the angle-adjustable bandpass filter module, each of the angle-adjustable bandpass filters selecting a different wavelength band of light that passes through the corresponding filter, and wherein one of the angle-adjustable bandpass filters can be selected by rotating the angle-adjustable bandpass filter module to select the specific wavelength band of light.

[0067] The step of selecting a specific wavelength of light of the present invention may further include a step of rotating an angle-adjustable bandpass filter. In the step of selecting a specific wavelength of light of the present invention, each of the plurality of angle-adjustable bandpass filters is rotated to adjust the angle of incidence of light with respect to the corresponding filter, and different wavelengths of light passing through the filter are selected depending on the angle of incidence, and a specific wavelength within a selected wavelength band of light may be selected by light passing through a selected angle-adjustable bandpass filter from the plurality of angle-adjustable bandpass filters at an angle of incidence specified by rotating the angle-adjustable bandpass filter.

[0068] The method for providing a tunable wavelength light source of the present invention may further include a step of rotating another angle-adjustable bandpass filter module, and in this case, by rotating the another angle-adjustable bandpass filter module and the angle-adjustable bandpass filter of the another angle-adjustable bandpass filter module, the bandwidth of a band having the specific wavelength within the selected wavelength band as its center wavelength can be adjusted.

[0069] In the method for providing a tunable wavelength light source of the present invention, the diffuse light source can be a light emitting diode (LED) or a lamp, and the mixing module can be an optical fiber, a liquid crystal light guide, or a rod lens.

[0070] Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are illustrative in all respects and are not limiting. [Explanation of symbols]

[0071] 1: Diffused light source 2: Parallel optical module 3: Angle adjustable bandpass filter module 4: Mixing module 21: Axicon lens 22: Lens 30: Angle adjustable bandpass filter

Claims

1. A tunable wavelength light source device, a diffuse light source that emits diffused light; a parallel optical module for collimating the light emitted from the diffuse light source, the parallel optical module including an axicon lens; an angle-adjustable bandpass filter module that passes light that has passed through the parallel light module and selects specific wavelengths of the light; and A variable wavelength light source device including a mixing module that corrects spatial errors in wavelengths determined by the angle of incidence of light passing through the angle-adjustable bandpass filter module.

2. the angle-adjustable bandpass filter module is a circular plate and includes a plurality of angle-adjustable bandpass filters; the plurality of angle-adjustable bandpass filters are arranged in a circular shape on an edge of the angle-adjustable bandpass filter module, and a selected wavelength band of light passing through each of the plurality of angle-adjustable bandpass filters is different; 2. The tunable wavelength light source device of claim 1, wherein one of the plurality of angle-adjustable bandpass filters is selected by rotating the angle-adjustable bandpass filter module to select a specific wavelength band of light.

3. each of the plurality of angle-adjustable bandpass filters is rotated to adjust an incident angle of light to the corresponding filter, and a wavelength of light passing through the filter is selected to be different depending on the incident angle; 3. The tunable wavelength light source device according to claim 2, wherein a specific wavelength within a selected wavelength band of light is selected by light passing through a selected angle-adjustable band-pass filter from the plurality of angle-adjustable band-pass filters at an angle of incidence specified by rotating the angle-adjustable band-pass filter.

4. The tunable wavelength light source device further includes another angle-adjustable bandpass filter module; 4. The tunable wavelength light source device according to claim 3, wherein the bandwidth of a band having the specific wavelength within the selected wavelength band as a center wavelength is adjusted by rotating the other angle-adjustable bandpass filter module and the angle-adjustable bandpass filter of the other angle-adjustable bandpass filter module.

5. 4. The tunable wavelength light source device according to claim 3, wherein an incident angle of light to the angle-adjustable bandpass filter is equal to or greater than 0 degrees and less than 90 degrees.

6. 2. The variable wavelength light source device according to claim 1, wherein the diffuse light source is a light emitting diode (LED) or a lamp.

7. 2. The tunable wavelength light source device according to claim 1, wherein the mixing module is an optical fiber, a liquid crystal light guide, or a rod lens.

8. 1. A method for providing a tunable wavelength light source, comprising: irradiating the light with a diffuse light source; collimating the light emitted from the diffuse light source with a parallel light module, the parallel light module including an axicon lens; selecting a specific wavelength of light by passing the light that has passed through the parallel light module with an angle-adjustable bandpass filter module; and A method for providing a tunable wavelength light source, comprising the step of correcting, in a mixing module, spatial errors in wavelength determined by the angle of incidence of light passing through said angle-adjusted bandpass filter module.

9. the angle-adjustable bandpass filter module is a circular plate and includes a plurality of angle-adjustable bandpass filters; the plurality of angle-adjustable bandpass filters are arranged in a circular shape on an edge of the angle-adjustable bandpass filter module, and a selected wavelength band of light passing through each of the plurality of angle-adjustable bandpass filters is different; 9. The method for providing a tunable wavelength light source of claim 8, further comprising the step of rotating an angle-adjustable bandpass filter module, wherein one angle-adjustable bandpass filter of the plurality of angle-adjustable bandpass filters is selected by rotating the angle-adjustable bandpass filter module to select a particular wavelength band of light.

10. rotating the angle-adjusted bandpass filter, each of the plurality of angle-adjustable bandpass filters is rotated to adjust an incident angle of light to the corresponding filter, and a wavelength of light passing through the filter is selected to be different depending on the incident angle; 10. The method for providing a tunable wavelength light source of claim 9, further comprising the step of rotating a selected one of the plurality of angle-adjustable bandpass filters such that light passes through the selected angle-adjustable bandpass filter at an angle of incidence specified by the angle-adjustable bandpass filter being rotated, thereby selecting a specific wavelength within a selected wavelength band of light.

11. 11. The method for providing a tunable wavelength light source of claim 10, further comprising the step of rotating another angle-adjustable bandpass filter module, wherein the step of rotating the another angle-adjustable bandpass filter module and the angle-adjustable bandpass filter of the another angle-adjustable bandpass filter module adjusts the bandwidth of a band having the specific wavelength within the selected wavelength band as its center wavelength.

12. 9. The method for providing a tunable wavelength light source according to claim 8, wherein the angle of incidence of light on the angle-tunable bandpass filter is greater than or equal to 0° and less than 90°.

13. 9. The method for providing a tunable wavelength light source of claim 8, wherein the diffuse light source is a light emitting diode (LED) or a lamp.

14. 9. The method for providing a tunable wavelength light source according to claim 8, wherein the mixing module is an optical fiber, a liquid crystal light guide, or a rod lens.

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