JP2010223748A - Photodetection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photodetection device, capable of precisely detecting a weak fluorescence signal, by removing noise components of an exciting light. <P>SOLUTION: The photodetection device 1 applies excitation light L emitted from an optical waveguide 10, with respect to a fluorescence sample W flowing through a channel 2 to detect a fluorescence signal S emitted from the fluorescence sample W. A hole 21, to which the optical waveguide 10 can be inserted, is provided in a fluorescence signal condensing lens 20 for condensing the fluorescence signal S, and an exciting light condensing lens 22 is disposed in the fluorescence signal condensing lens 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a photodetection device, and more particularly to a photodetection device that is used in the field of biotechnology measurement, such as a flow cytometer or an electrophoresis device, for measuring a weak fluorescence signal.

  In the field of biotechnology measurement, an optical measurement device that detects a fluorescent signal emitted from a sample by irradiating the sample with excitation light is used. Excitation light generated by a laser light source, a light emitting diode (LED), or the like has been detected by irradiating the sample through a fluorescent condensing lens (see, for example, Patent Document 1).

JP 2005-535871 A

However, in the optical measurement device described in Patent Document 1, excitation light is reflected on the surface or inside of the condensing lens in the photodetector for detecting the fluorescence signal, and the reflected excitation light is somewhat reduced. It was incident and became a noise component. Since the fluorescence signal is weak light, there has been a problem that the detection sensitivity of the photodetector is lowered due to the influence of the noise component described above.
In addition, there is a method of removing the above-described noise component using an optical filter by utilizing the difference in wavelength between the excitation light and the fluorescence signal, but the light intensity of the fluorescence signal is attenuated somewhat due to the influence of the optical filter. In addition, there is a problem that the detection sensitivity of the photodetector is lowered.
Accordingly, an object of the present invention is to provide a photodetector that can accurately detect a weak fluorescent signal by removing a noise component of excitation light in order to solve the above-described problems.

  In order to solve the above problems, the photodetector of the present invention irradiates the fluorescent sample flowing in the flow path with excitation light emitted from the optical waveguide, and generates a fluorescent signal emitted from the fluorescent sample. In the light detection device for detection, the fluorescent signal condensing lens that condenses the fluorescent signal is provided with a hole portion into which the optical waveguide can be inserted.

In the light detection device of the present invention, preferably, the fluorescence signal condensing lens is provided with an excitation light condensing lens that condenses the excitation light emitted from the optical waveguide and irradiates the fluorescent sample. It is characterized by.
In the light detection device of the present invention, preferably, the hole is a non-through hole provided in the fluorescent signal collecting lens.
In the photodetecting device of the present invention, preferably, the hole is a through hole provided in the fluorescent signal condensing lens.
The light detection device of the present invention is preferably characterized in that the excitation light condensing lens is provided at an end of the optical waveguide.

The light detection device of the present invention is preferably characterized in that the excitation light condensing lens is integrally connected to an end of the optical waveguide.
The light detection device of the present invention is preferably characterized in that the diameter of the optical waveguide and the diameter of the excitation light condensing lens are the same.

The photodetecting device of the present invention is preferably characterized in that a coating for blocking the excitation light is applied to an outer peripheral portion of the optical waveguide.
The photodetection device of the present invention is preferably characterized in that a taper portion is provided in the hole portion of the fluorescent signal condensing lens.
The optical detection device of the present invention is preferably characterized in that a tapered portion is provided at the tip of the optical waveguide.

  According to the present invention, it is possible to provide a photodetector that can accurately detect a weak fluorescent signal by removing a noise component of excitation light.

1 is a diagram illustrating a first preferred embodiment of a light detection apparatus according to the present invention. It is a figure which shows the B part and C part of the photon detection apparatus shown in FIG. It is a figure which shows preferable 2nd Embodiment of the photon detection apparatus of this invention. It is a figure which shows F part and G part of the photon detection apparatus shown in FIG. It is a figure which shows another embodiment of this invention. It is a figure which shows another embodiment of this invention. It is a figure which shows another embodiment of this invention. It is a figure which shows another embodiment of this invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
(First embodiment)
1 and 2 show a first preferred embodiment of the photodetector of the present invention. FIG. 1 is a front view showing the configuration of the photodetecting device 1. 2A is a view of the portion B of the light detection device 1 shown in FIG. 1 viewed from the P direction, and FIG. 2B is a view of the portion C of the light detection device 1 shown in FIG. 1 from the R direction. FIG.

1 and FIG. 2A irradiates the fluorescent sample W flowing in the flow path 2 with the excitation light L emitted from the optical waveguide 10 to irradiate the fluorescent sample W. Is a device for detecting a weak fluorescent signal S emitted from the.
The flow path 2 shown in FIGS. 1 and 2A is a transparent tube such as a glass tube having a rectangular cross section as an example. The flow path 2 is arranged in the X direction in FIGS. 1 and 2.
The fluorescent sample W is a fine particle such as a cell, for example, and generates a fluorescent signal S when irradiated with the excitation light L.

  As shown in FIGS. 1 and 2A, the fluorescent signal collecting lens 20 is disposed along the side surface 2B of the flow path 2, and the fluorescent signal collecting lens 20 includes an end of the optical waveguide 10. A hole 21 into which the portion 11 can be inserted is provided. The fluorescent signal condensing lens 20 condenses the fluorescent signal S on the detector 30.

The hole 21 of the fluorescent signal condenser lens 20 is a hole having a circular cross section, and is formed along the Z direction at the center position of the fluorescent signal condenser lens 20. In addition, the excitation light condensing lens 22 is disposed at the innermost position of the hole 21 and in the vicinity of the side surface 2B of the flow path 2. The excitation light condensing lens 22 condenses the excitation light L emitted from the end 11 of the optical waveguide 21 and irradiates the fluorescent sample W.
The optical waveguide 10 is an optical fiber, for example, and has a core part and a clad part covering the periphery of the core part. A light source 90 is connected to the optical waveguide 10, and the light source 90 supplies the excitation light L to the optical waveguide 10, and the optical waveguide 10 propagates the excitation light 1P0.

The inner diameter H <b> 1 of the hole 21 shown in FIG. 2A only needs to be larger than the outer diameter H <b> 2 of the optical waveguide 10. However, when the optical waveguide 10 is positioned with respect to the X direction, the Z direction, and the Y direction by the hole portion 21, the inner diameter H1 of the hole portion 21 is 0.01 mm to 0 mm compared to the outer diameter H2 of the optical waveguide 10. Preferably it is larger by 3 mm.
As shown in FIG. 2B, the detector 30 is provided concentrically around the optical waveguide 10. The detector 30 is a light receiving sensor that receives the fluorescence signal S shown in FIG. 2A, and is formed in a ring shape. The detector 30 and the light source 90 are connected to the control unit 100.

Next, an operation example of the photodetection device 1 shown in FIGS. 1 and 2 will be described.
As shown in FIG. 2A, the fluorescent sample W flows in the X1 direction in the flow path 2. The end 11 of the optical waveguide 10 is inserted into the hole 21 so that the end 11 of the optical waveguide 10 faces the excitation light collecting lens 22.

When the optical waveguide 10 guides the excitation light L generated from the light source 90 to the excitation light condensing lens 22, the excitation light condensing lens 22 condenses the excitation light L on the fluorescent sample W and irradiates it.
In this way, when the excitation light L emitted from the optical waveguide 10 is irradiated to the fluorescent sample W flowing in the flow path 2, the fluorescent signal S is generated from the fluorescent sample W as illustrated by a broken line. To do.
The generated fluorescence signal S is collected by the fluorescence signal collecting lens 20 shown in FIGS. 1 and 2B and detected by the detector 30. The detector 30 can convert the fluorescence signal S into an optical / electrical signal and send it to the control unit 100.

  In the photodetector 1 shown in FIGS. 1 and 2, the hole 21 of the fluorescence signal condenser lens 20 is closed by the excitation light condenser lens 22, so that the hole 21 does not penetrate in the Z direction. First, the fluorescent signal collecting lens 20 has a non-penetrating hole 21. The end portion 11 of the optical waveguide 10 employs a structure that is directly inserted into the hole portion 21, and the relative positioning operation between the end portion 11 of the optical waveguide 10 and the fluorescence signal condensing lens 20 becomes easy. . In addition, since the excitation light L is not reflected by the excitation light condensing lens 22 in the light detection apparatus 1, it is possible to accurately detect weak fluorescence by removing the noise component of the excitation light.

(Second Embodiment)
3 and 4 show a second preferred embodiment of the photodetector of the present invention. FIG. 3 is a front view showing the configuration of the photodetecting device 1B. 4A is a view of the portion F of the photodetector 1B shown in FIG. 3 as viewed from the P direction, and FIG. 4B is a view of the portion G of the photodetector 1 shown in FIG. 3 from the R direction. FIG.
The photodetector 1B shown in FIGS. 3 and 4 differs from the photodetector 1 shown in FIGS. 1 and 2 in the shape of the hole 21B of the fluorescent signal collecting lens 20 and the end 11B of the optical waveguide 10. It is the shape. The other components of the photodetecting device 1B shown in FIGS. 3 and 4 are substantially the same as the corresponding components of the photodetecting device 1 shown in FIGS. Is used.

  As shown in FIG. 4A, the shape of the hole 21B of the fluorescence signal condensing lens 20 is a tapered portion 21T that spreads out in the Z1 direction. The shape of the end portion 11B of the optical waveguide 10 is a tapered portion 11T that tapers as it goes to Z2. As described above, by adopting the shape of at least one of the tapered portion 21T and the tapered portion 11T, the end portion 11B of the optical waveguide 10 can be more easily inserted into the hole portion 21.

(Other embodiments)
5A and 5B show another embodiment of the present invention.
Both the hole 21 of the fluorescent signal focusing lens 20 in the first embodiment shown in FIGS. 1 and 2 and the hole 21B of the fluorescent signal focusing lens 20 in the second embodiment shown in FIGS. 3 and 4 are both excited. Since it is closed by the light condensing lens 22, it has a non-penetrating hole structure. In this way, the excitation light condensing lens 22 is arranged in the hole portion to form a non-penetrating hole portion structure, so that the excitation light L is reliably condensed, and the condensed excitation light L is the fluorescent sample. Irradiation to W can be performed with high accuracy.
Furthermore, by optimizing the structure of the fluorescent signal condensing lens 20 and the core diameter of the optical waveguide 10, the diameter size of the excitation light L irradiated to the fluorescent sample W can be easily set to a very small size of several μm to 100 μm. Can be set.

  On the other hand, in the embodiment shown in FIG. 5A, the hole 21B of the fluorescence signal condensing lens 20 is a through hole, and in the same manner in the embodiment shown in FIG. The hole 21 of the signal condenser lens 20 is a through hole. However, in the embodiment shown in FIG. 5A, a tapered portion 21T is formed in the hole portion 21B of the fluorescent signal collecting lens 20. In this way, when the hole is penetrating, the reflected light of the excitation light on the inner surface or the surface of the fluorescent signal collecting lens 20 is further reduced, resulting in a reduction in noise components and a maximum sensitivity ( Resolution) is improved 5 to 10 times.

6 (A) to 6 (D) show still another embodiment of the present invention.
In each of the embodiments, the excitation light condensing lens 22 is also disposed in the holes 21B and 21, and is a non-penetrating fluorescent signal condensing lens 20.
In each embodiment shown in FIGS. 6A and 6B, a tapered portion 21 </ b> T is formed in the hole portion 21 </ b> B of the fluorescent signal collecting lens 20. However, in each of the embodiments shown in FIGS. 6C and 6D, the hole 21 of the fluorescent signal collecting lens 20 is not formed with a tapered portion.

In each embodiment of FIG. 6A, the excitation light condensing lens 22 disposed in the hole 21B is a single-sided concave lens, and the concavity 22M of the excitation light condensing lens 22 is connected to the end 11 of the optical waveguide 10. Is located on the opposite side, ie outside.
In each embodiment of FIG. 6B, the excitation light condensing lens 22 arranged in the hole 21B is a single-sided convex lens, and the convex portion 22N of the excitation light condensing lens 22 is the end 11 of the optical waveguide 10. It is located on the side facing the side, that is, on the inner side.

In each embodiment of FIG. 6C, the excitation light condensing lens 22 disposed in the hole 21 is a single-sided concave lens, and the concavity 22M of the excitation light condensing lens 22 is connected to the end 11 of the optical waveguide 10. Is located on the opposite side, ie outside.
In each embodiment of FIG. 6D, the excitation light condensing lens 22 disposed in the hole 21 is a single-sided convex lens, and the convex portion 22N of the excitation light condensing lens 22 is the end 11 of the optical waveguide 10. It is located on the side facing the side, that is, on the inner side.

7A and 7B show still another embodiment of the present invention.
7A and 7B show another example of the shape of the excitation light condensing lens. A tapered portion 21T is formed in the hole 21B of the fluorescent signal condensing lens 20. FIG. However, the tapered portion may not be formed in the hole portion of the fluorescent signal collecting lens 20.
In FIG. 7A, the excitation light condensing lens 22K is a convex lens. This convex lens has a shape suitable for the shape of the excitation light L irradiated to the fluorescent sample. In FIG. 7B, the excitation light condensing lens 22L is a rod-shaped lens. The diameter of the excitation light condensing lens 22L and the diameter of the end 11 of the optical waveguide 10 are the same. If the diameter of the excitation light condensing lens 22L and the end 11 of the optical waveguide 10 are integrated, the excitation light collecting Since the optical lens 22L can be fixed to the end portion 11 of the optical waveguide 10 at the same time, the number of members and the number of assembly steps can be easily reduced.

FIG. 8A shows an example of the shape of the optical waveguide 10 described above. The optical waveguide 10 is an optical fiber, and has a core portion 10C and a cladding portion 10D covering the core portion 10C.
FIG. 8B shows an example in which the cladding portion 10D of the optical waveguide 10 is covered with a coating 10R. Thereby, it is possible to prevent the excitation light propagating through the optical waveguide 10 from leaking to the outside from the cladding portion 10D of the optical waveguide 10 and to reduce noise. The coating 10R is, for example, a resin or metal coating, and can improve the light detection sensitivity.

  Furthermore, by selecting a material that reflects the wavelength of the fluorescent signal well as a material for forming the coating 10R that blocks the excitation light, more fluorescent signals generated from the fluorescent sample can be collected in the detector, Detection sensitivity is improved. Specifically, when the wavelength of the excitation light is blue (wavelength of about 488 nm) and the wavelength of the fluorescence signal is green (wavelength of about 514 nm), the coating 10R has a high reflectance of green (wavelength of about 514 nm) light. .

  The light detection device of the present invention is a light detection device that irradiates a fluorescent sample flowing in a flow path with excitation light emitted from an optical waveguide and detects a fluorescent signal emitted from the fluorescent sample, The fluorescent signal condensing lens that condenses the fluorescent signal is provided with a hole into which the optical waveguide can be inserted. As a result, the optical waveguide can be inserted and held in the hole of the fluorescent signal condensing lens, and the tip of the optical waveguide can be placed close to the fluorescent sample, so that the noise component of the excitation light is removed and the weak fluorescent signal is accurate. Can be detected well

The fluorescence signal condensing lens is provided with an excitation light condensing lens that condenses the excitation light emitted from the optical waveguide and irradiates the fluorescent sample. Thereby, the excitation light is condensed by the excitation light condensing lens and can be reliably irradiated to the fluorescent sample.
When the hole is a through hole provided in the fluorescent signal collecting lens, the reflected light of the excitation light on the inner surface or the surface of the fluorescent signal collecting lens is reduced, so that noise can be reduced.
An excitation light condensing lens is provided at the end of the optical waveguide. As a result, the excitation light from the end of the optical waveguide can be efficiently and reliably condensed by the excitation light condensing lens and can be reliably irradiated to the fluorescent sample.

An excitation light condensing lens is integrally connected to the end of the optical waveguide. This facilitates fixing of the excitation light condensing lens.
The diameter of the optical waveguide and the diameter of the excitation light condensing lens are the same. As a result, the excitation light can be reliably collected from the optical waveguide via the excitation light condensing lens, and the fluorescent sample can be reliably irradiated.

The outer periphery of the optical waveguide is provided with a coating that blocks excitation light. As a result, the excitation light propagating through the optical waveguide can be prevented from leaking outside from the optical waveguide, and noise can be reduced.
A taper portion is provided in the hole portion of the fluorescent signal condensing lens. Thereby, the optical waveguide can be easily inserted and held in the hole.
A tapered portion is provided at the tip of the optical waveguide. Thereby, the optical waveguide can be easily inserted and held in the hole.

  In the photodetector of the present invention, the excitation light reflected on the surface or inside of the condenser lens can be removed from the photodetector for detecting fluorescence, so that fluorescence measurement with high sensitivity (resolution) can be performed. There are effects that can be performed. Furthermore, since the hole into which the optical waveguide is inserted is provided, the positioning of the optical waveguide, that is, the positioning of the excitation light can be performed accurately. Moreover, since an optical waveguide is used, no special lens or positioning device is required even if the diameter of the excitation light is reduced to 50 μm or less, and the device can be miniaturized and the device can be easily integrated. Become.

By the way, this invention is not limited to the said embodiment, A various modified example is employable.
For example, a plurality of holes may be formed in the excitation light condensing lens, and the end portions of the optical waveguide may be inserted into these holes, respectively. The cross-sectional shape of the flow path is not limited to a rectangular shape, and other shapes such as a circular shape or an elliptical shape can also be adopted. As the light source, a laser light source, a light emitting diode, or the like can be employed. Each embodiment can be configured in any combination.

DESCRIPTION OF SYMBOLS 1 Photodetector 2 Flow path 10 Optical waveguide 11 End 20 of optical waveguide Fluorescent signal condensing lens 21 Hole 30 of fluorescent signal condensing lens Detector W Fluorescent sample L Excitation light S Fluorescent signal

Claims (10)

A photodetection device that irradiates excitation light emitted from an optical waveguide to a fluorescent sample flowing in a flow path and detects a fluorescent signal emitted from the fluorescent sample,
The fluorescent signal condensing lens which condenses the fluorescence signal is provided with a hole portion into which the optical waveguide can be inserted.   2. The excitation light condensing lens that condenses the excitation light emitted from the optical waveguide and irradiates the fluorescence sample is disposed in the fluorescence signal condensing lens. The photodetection device described in 1.   The photodetecting device according to claim 1, wherein the hole is a non-through hole provided in the fluorescent signal collecting lens.   The photodetection device according to claim 1, wherein the hole is a through hole provided in the fluorescent signal condensing lens.   The photodetection device according to any one of claims 1 to 4, wherein the excitation light condensing lens is provided at an end of the optical waveguide.   The photodetecting device according to claim 5, wherein the excitation light condensing lens is integrally connected to an end of the optical waveguide.   The light detection device according to claim 6, wherein a diameter of the optical waveguide and a diameter of the excitation light condensing lens are the same.   The optical detection apparatus according to claim 1, wherein a coating that blocks the excitation light is provided on an outer peripheral portion of the optical waveguide.   The photodetection device according to any one of claims 1 to 8, wherein a tapered portion is provided in the hole portion of the fluorescent signal condensing lens. The optical detection device according to claim 9, wherein a tip portion of the optical waveguide is provided with a tapered portion.

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