GB2568307A

GB2568307A - Spectral excitation device

Info

Publication number: GB2568307A
Application number: GB1718760.0A
Authority: GB
Inventors: Trump Martin; Retzlaff Rüdiger; Gröhbühl Bernd
Original assignee: Stratec Biomedical AG
Current assignee: Stratec Biomedical AG
Priority date: 2017-11-14
Filing date: 2017-11-14
Publication date: 2019-05-15
Also published as: GB201718760D0

Abstract

A light emitting device 11 for use in analyser systems includes at least one or optionally an array of light sources 1 such as a light emitting diode, multi-colour LED, OLED, converter LED or laser diode emitting light at a single or small range of defined wavelengths at a time, means for collimating the light such as a collimating lens 2 and means for sharpening the range of defined wavelength such as a beam splitter 6 or filter (3, fig 1). The light beam 10 is focused onto a sample for example for exciting fluorescence. The device may include a rigid light guide 4 such as an optical fibre 7 or optical lens arrangement and may be used in apparatus such as microscopes or luminescence analyzers. A beam homogenizer 9 may collect and guide the light 10 into the light guide 4. The light guide 4 may direct the light through a vessel holder (5, fig 1).

Description

SPECTRAL EXCITATION DEVICE

DESCRIPTION

Field of the invention [0001] The field of the invention relates to a device and a method for spectral excitation as well as a method for luminescence and microscopic analysis of a sample in an analyzer.

Background of the invention [0002] Luminescence analysis of samples is part of everyday practice in laboratory work and clinical diagnostics. Luminescence analyzers, for example as part of a diagnostic instrument or microscope, usually need a light source to excite a sample with light of a certain wavelength thereby enabling measurement and analyzing steps.

[0003] Fluorescence is a form of luminescence and occurs frequently in nature for example in some minerals and in various biological materials. Fluorometers are a kind of luminescence analyzers measuring fluorescence.

[0004] Fluorescence has many practical applications including mineralogy, gemology, fluorescence spectroscopy, chemical sensors, fluorescent labelling, dyes, biological detectors, cosmic-ray detection and fluorescent lamps.

[0005] Typically it is desired to excite the sample with a certain wavelength.

[0006] It is essential to use spectral light of defined wavelengths and small bandwidths for fluoroscopic measurements. Small bandwidths, typically between 10 nm and 50 nm, enable selective excitation of a dye and separation of excitation and emission wavelengths.

[0007] A certain crosstalk from excitation to emission channel is unavoidable, as the spectra of excitation and emission overlap. This crosstalk can be reduced by choosing suitable angles between excitation and emission channel and using customized filters.

[0008] In the prior art it is common to use a white light source with a broad spectrum of light wavelengths subsequently followed by filters or beam splitters with small bandwidths. Commonly a drive is used to exchange the specific filters in the light path in order to emit light of a certain wavelength.

[0009] Light of different wavelengths can, for example, be separated by a prism. Instead of using filters, the bandwidth of the emitted light can be limited by means of optical refraction. The optical refraction can for example be caused by a prism, a slit, or a grid, like an echelle grid for instance.

[0010] Devices of the prior art have several disadvantages. A large amount of heat is produced by the light source providing a broad range of wavelengths that are subsequently reduced to a small bandwidth by filters. Moreover, the procedure of exchanging filters is time consuming and causes inaccuracies. Overall the devices of the prior art are expensive, complex and they need intensive care and maintenance.

Object of the invention [0011] It is an object of the invention to provide a device emitting and guiding light of a certain wavelength or range of wavelengths or several wavelengths or ranges of wavelengths to a sample for spectral excitation of the sample enabling measurement and analysis of the light emitted by the sample in a process that is more efficient in terms of energy consumption, costs and space and furthermore shows less mechanical complexity, increased accuracy and wavelength stability, produces less heat and enables fast measurement.

Summary of the invention [0012] The instant invention provides a light emitting device for use in analyzer systems, wherein the device comprises at least one light source emitting light of a defined wavelength or small range of defined wavelengths at a time for exciting fluorescence, at least one collimating lens for collimating the emitted light, filter or a beam splitter for sharpening the range of defined wavelength, wherein the at least one light source comprises at least one single or multi-color LED, converter LED, OLED or laser diode. The at least one light source can be arranged in or as part of an array of multiple identical or different light sources [0013] In a further aspect of the invention, the device may further comprise at least one light guide for guiding the light of defined wavelength.

[0014] The at least one light source of the device may be selected from the group comprising LED, OLED and laser diodes. The light source may is configured to emit a single color or comprise at least one multi-color light source such as - without limitation - LED, OLED, laser diodes, converter LED, array of multi-color LEDs, OLEDS and laser diodes or at least one array of converter LEDs. Furthermore, light sources may be arranged on the same chip.

[0015] It is envisaged that the device comprises a controller for controlling the at least one light source separately or in groups.

[0016] The device may further comprise at least one optical element selected from the group comprising a concentrating reflector, a collecting lens, a lens array and a beam homogenizer.

[0017] It is intended that the device may comprise a vessel holder and that at least one light guide connected to the vessel holder, wherein the vessel holder itself can be the light guide.

[0018] The at least one light guide may be rigid and may be an optical fiber or an optical lens or arrangement of lenses.

[0019] The filter in the device may be a coating on the planar side of the collimating lens.

[0020] It is envisaged that laser diodes are used instead of LEDs.

[0021] It is further envisaged that the device may be used in microscopes or luminescence analyzers.

[0022] Moreover, it is intended to further provide a method for spectral excitation of a sample in analyzer systems, comprising the steps of emitting light of at least one defined wavelength or small range of defined wavelengths by at least one light source emitting light of the defined wavelength or small range of defined wavelengths at a time, collecting and forming the light to an almost collimated beam form, sharpening the range of defined wavelengths by narrowing the bandwidth, collecting and guiding the light into a light guide, and exciting a sample by focusing the light on the sample.

[0023] It is also intended to provide a method for luminescence analysis of a sample in analyzer systems, comprising the steps of emitting light of at least one defined wavelength or small range of defined wavelengths by at least one light source emitting light of the defined wavelength or small range of defined wavelengths at a time, collecting and forming the light to an almost collimated beam form, sharpening the range of defined wavelengths by narrowing the bandwidth, collecting and guiding the light into a light guide, exciting a sample by focusing the light on the sample, measuring light emitted by the excited sample, and analyzing the measured light.

[0024] Furthermore, it is intended to provide a method for microscopic analysis of a sample in an analyzer system, comprising the steps of emitting light of at least one defined wavelength or small range of defined wavelengths by at least one light source emitting light of the defined wavelength or small range of defined wavelengths at a time, collecting and forming the light to an almost collimated beam form, sharpening the range of defined wavelengths by narrowing the bandwidth, collecting and guiding the light into a light guide, exciting a sample by focusing the light on the sample, creating an image with the light emitted by the excited sample, and analyzing the created image.

Summary of the figures [0025] The invention will now be described on the basis of figures. It will be understood that the embodiments and aspects of the invention described in the figures are only examples and do not limit the protective scope of the claims in any way. The invention is defined by the claims and their equivalents. It will be understood that features of one aspect or embodiment of the invention can be combined with a feature of a different aspect or aspects of other embodiments of the invention. It shows:

Figure 1: Schematic of a light emitting device comprising filters and a rigid light guide.

Figure 2: Schematic of a light emitting device comprising beam splitters, a beam homogenizer and optical fibers.

Detailed description of the invention [0026] The invention provides a device showing a highly integrated design, emitting and guiding light to a sample for spectral excitation of the sample enabling measurement and analysis of the light emitted by the sample in a process that is more efficient in terms of energy consumption, costs and space and furthermore shows increased accuracy and wavelength stability, produces less heat and enables fast measurement while dispensing with moving parts and showing reduced mechanical complexity.

[0027] The invention describes a light emitting device 11 comprising at least one light source 1 emitting light of a certain wavelength or small range of wavelengths encompassing a range between ten and three hundred nanometers at a time, collimating lens 2, filter 3 or beam splitter 6 to sharpen the light by narrowing the bandwidth, and light guide 4. The light guide 4 may comprise at least one optical focus element for example to focus the exciting light on a sample to be analyzed and contained in a vessel held by a vessel holder 5. The at least one optical focus element may be selected from the group comprising but not limited to a concentrating reflector, a collecting lens and a beam splitter.

[0028] The light source in the light emitting device 11 comprises a multi-color or converter light emitting diode (LED) or an array of such LEDs, wherein an array of LEDs comprises at least two LEDs. The LEDs may be on the same chip and be lightened separately and/or together. The light emitting device 11 may further comprise a controller allowing to control the light sources separately and/or together. As the light source or LEDs in particular emit light only of a certain wavelength or a small range of wavelengths at a time, the initial spectral emission is already limited.

[0029] One aspect of the invention describes a light emitting device 11 comprising at least one filter 3 and rigid light guide 4. The emitted light is collected and formed to an almost collimated beam form by at least one collimating lens 2. The light is subsequently sharpened by at least one filter 3 on the light path. This can be realized by a coating on the planar side of the collimation lens 2. The filtered light is collected and guided into a light guide 4.

[0030] Another aspect of the invention describes a light emitting device 11 comprising at least one beam splitter 6 and optical fiber 7. The emitted light is collected and formed to an almost collimated beam form by at least one collimating lens 2. The light is subsequently sharpened by at least one beam splitter 6 on the light path. The beam splitter 6 deflects only light of a defined wavelength. Other wavelengths pass the beam splitter 6 without being deflected and can be eliminated via a cover plate 8. The sharpened light is collected and guided into the light guide 4 by a beam homogenizer 9 which converts the input light beam into a well-defined light beam with homogenized intensity. The homogenized light beam 10 is then launched into an optical fiber 7.

It is furthermore possible to use laser diodes instead of LEDs. Moreover, lens arrays 12 may be used after the filter or beam splitter to launch the light into a light guide or optical fiber.

[0031] The advantages of the invention of the present disclosure can be summarized as follows:

a. The invention consumes less energy and produces less heat because only certain wavelengths or ranges of wavelengths are emitted at a time by the light source instead of a broad range of wavelengths.

b. The absence of moving parts reduces mechanical complexity and space and enables faster measurements.

c. The invention is less expensive.

d. The invention provides increased wavelength stability and accuracy.

e. The invention achieves increased efficiency.

[0032] According to the present invention a vessel may be a reaction vessels or any kind of receptacle including cuvettes, tubes and well-plates.

[0033] Spectral excitation of a sample means excitation of a sample with light.

[0034] Fluorescence is a form of luminescence and describes the emission of light by a substance that has absorbed light or other electromagnetic radiation. The emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation. Fluorescent materials stop glowing immediately after removal of the excitation source.

Detailed description of the figures [0035] Figure 1 shows a light emitting device 11, wherein two light sources 1 are each coupled to a collimating lens 2 and the light is subsequently filtered by filters 3 before entering a rigid light guide 4, guiding the light through a vessel holder 5.

[0036] Figure 2 shows a light emitting device 11, wherein always five single light sources 1 form an array and wherein in total six arrays each emit light of a different color. The light is collected and formed by collimating lenses 2, before it is sharpened by beam splitters 6. The beam splitters 6 deflect only light of a defined wavelength, while other wavelengths pass the beam splitter 6 straight on and can be eliminated via a cover plate 8. The sharpened light is collected and guided into the light guide 4 by a beam homogenizer 9, which converts the input beam into a well-defined light beam 10 with homogenized intensity before it enters the optical fibers 7.

Reference Numerals light source collimating lens filter light guide vessel holder beam splitter optical fiber cover plate beam homogenizer light beam light emitting device lens array fiber connector

Claims

1. A light emitting device for use in analyzer systems, wherein the device comprises at least one light source emitting light of a defined wavelength or small range of defined wavelengths at a time for exciting fluorescence, at least one collimating lens for collimating the emitted light, a filter or a beam splitter for sharpening the range of defined wavelength, wherein the at least one light source comprises at least one single or multi-color LED, converter LED, OLED or laser diode.

2. The device according to claim 1, wherein the at least one light source is arranged in or as part of an array of multiple identical or different light sources.

3. The device according to any one of claims 1 or 2, further comprising at least one light guide for guiding the light of defined wavelength.

4. The device according to any one of claims 1 to 3, wherein the light sources are arranged on a same chip.

5. The device according to any one of claims 1 to 4, further comprising a controller for controlling the at least one light source separately or in groups.

6. The device according to any one of claims 1 to 5, further comprising at least one optical element selected from the group comprising a concentrating reflector, a collecting lens, a lens array and a beam homogenizer.

7. The device according to any one of claims 1 to 6, wherein the device further comprises a vessel holder.

8. The device according to claim 7, wherein at least one light guide is connected to the vessel holder or the vessel holder itself comprises a light guide.

9. The device according to any one of claims 1 to 8, wherein the at least one light guide is rigid.

10. The device according to any one of claims 1 to 9, wherein the at least one light guide is an optical fiber.

11. The device according to any one of claims 1 to 10, wherein the filter is a coating on a planar side of the collimating lens.

12. The use of a device according to any one of claims 1 to 11 in microscopes or luminescence analyzers.

13. A method for spectral excitation of a sample in analyzer systems, comprising the steps of emitting light of at least one defined wavelength or small range of defined wavelengths by at least one light source emitting light of the defined wavelength or small range of defined wavelengths at a time, collecting and forming the light to an almost collimated beam form, sharpening therange of defined wavelengths by narrowing the bandwidth, collecting and guiding the light into a light guide, and exciting a sample by focusing the light on the sample.

14. The method of claim 13 further comprising the steps of:

- measuring light emitted by the excited sample, and analyzing the measured light.

15. The method of claim 14 further comprising the steps of:

creating an image with the light emitted by the excited sample, and analyzing the created image.