Single lens path using mirrors and beam splitters for emission and excitation in a customizable optical head

Abstract

This paper discloses a small form factor optical head that defines a single optical path. The optical head includes a housing, a lens positioned on or within the housing, and a light source positioned within the housing to emit excitation light. A mirror positioned within the housing reflects the excitation light to the lens and receives the emitted light returning through the lens, and a beam splitter positioned within the housing guides the excitation light to the lens and the emitted light to a detector, which receives the emitted light after it returns through the lens and beam splitter. The lens, mirror, and beam splitter define a single optical path for the excitation and emitted light. This paper also discloses a method for optical analysis.

Description

Background Technology

[0001] The following description relates to the design of an optical system and a compact, customizable optical head that uses a single optical path for excitation and emission and is intended for applications such as fluorescence assays, spectroscopic assays, or other optical analysis systems that require a compact, integrated design.

[0002] Fluoresight meters measure parameters of visible-spectral fluorescence. Specifically, they measure the presence and quantity of specific molecules in a medium by measuring the intensity and wavelength distribution of the emission spectrum after excitation by light of a specific spectrum. In optical systems such as fluorometers, separate paths are typically used for excitation light and emission detection, which increases the complexity and size of the device.

[0003] Typically, small shape factor fluorometers use a dual-beam optical head. The emitted beam and excitation beam each have separate paths and lenses within the optical head. The excitation beam passes through a filter and then through the sample. After the excitation beam reaches the target, the sample generates an emitted beam, which passes through a lens, an attenuator, and is measured by a photodiode or measuring device. The beam passes through a separate lens within the fluorometer optical head. A transducer detects the fluorescence emitted by the sample and the filtered beam, converting them into electrical signals for interpretation.

[0004] One drawback of known devices is their use of inefficient optical geometry. That is, these small form factor optics use a measurement angle of less than 90° between the LED and the photodiode. This requires tedious alignment of the optics during assembly and maintenance and often relies on complex arrangements of lenses and mirrors, increasing the system's size and complexity.

[0005] Therefore, there is a need for an optical head with a segmented configuration for fluorometers. It is desirable that such an optical head uses segments assembled in a specific manner to encapsulate filters and mirrors, allowing for precise alignment for advanced fluorescence measurements. More desirable is that such an optical head includes upper, middle, and lower housing segments to provide such precise component alignment. It is also desirable that in such an optical head, the excitation and emission beams converge or share the same optical path to and from the target behind the mirror, thus requiring only a single lens. Summary of the Invention

[0006] In one aspect, a small form factor optical head defines a single optical path. The optical head includes a housing, a lens positioned on or within the housing, and a light source positioned within the housing. The light source is configured to emit excitation light. In embodiments, the light source may be an LED or a laser for generating the excitation light.

[0007] The optical head includes a mirror positioned within a housing to reflect excitation light to a lens and receive emitted light returning from the material being analyzed through the lens. To achieve a single optical path, the optical head includes a beam splitter positioned within the housing to direct the excitation light to the lens and the emitted light to a detector. The detector may be, for example, a photodiode. The detector is positioned to receive the emitted light after it has passed through the lens and beam splitter and returned.

[0008] Lenses, mirrors, and beam splitters define a single optical path for both excitation and emission of light. In some embodiments, the lens is adjustable. The lens may be a spherical lens.

[0009] The optical head may also include one or more filters. The filters may be emission filters in the emission beam and / or excitation filters in the excitation beam.

[0010] In one embodiment, the optical head includes a lens block. A reflector and a beam splitter may be received in a first side of the lens block, and a lens is located in or on a second side of the lens block. The lens block may include a first lens block segment configured to receive a light source, a second lens block segment configured to receive one or more filters, and a third lens block segment configured to receive a reflector and a beam splitter. The first, second, and third lens block segments may be fixed to each other and positioned as a unit within a housing.

[0011] In one aspect, the small form factor optical head defines a single optical path and includes a housing, a lens, a light source positioned in the housing, a photodiode positioned in the housing, and a lens block positioned in or on the housing.

[0012] The optical head includes a mirror positioned within a housing, and a first filter and a second filter positioned within the housing. A lens block is configured to receive a light source, a photodiode, the first and second filters, the mirror, and a beam splitter on its first side, and a lens is positioned on a second side of the lens block. The lens is configured to focus excitation light, generated by an LED or laser, which travels through an excitation filter (if desired), is then reflected from the mirror along a path to the beam splitter, and passes through the lens. Emitted light is generated at the source and travels through the lens to the beam splitter and the emission filter (if desired), and then to the detector. The lens can be, for example, a spherical lens. The lens can be adjustable.

[0013] In another aspect, a method for optical analysis includes: providing an optical head having: a housing; a lens positioned on or within the housing; a light source positioned within the housing, the light source being configured to emit excitation light; a mirror positioned within the housing to reflect the excitation light to the lens and receive emitted light returning through the lens; a beam splitter positioned within the housing to guide the excitation light to the lens and guide the emitted light; and a detector positioned to receive the emitted light after it returns through the lens and the beam splitter, wherein the lens, mirror, and beam splitter define a single optical path for the excitation light and the emitted light; emitting a light beam from the light source; receiving the emitted light beam; and analyzing the emitted light beam.

[0014] In another aspect, a small shape factor optical head (e.g., for a fluorometer) includes a housing, light-emitting diodes (LEDs) and photodiodes mounted to a printed circuit board, lenses and lens blocks positioned within the housing. The lens blocks include a first lens block segment, a second lens block segment, and a third lens block segment, a first filter and a second filter, a reflector, and a beam splitter.

[0015] The first lens block segment is configured to receive an LED and a photodiode, the second lens block segment is configured to receive a first filter and a second filter, and the third lens block segment is configured to receive a reflector and a lens beam splitter on its first side and a lens on its second side. The first, second, and third lens block segments are fixed to each other and positioned as a unit within the housing. The excitation beam and the emission beam converge or share the same optical path to and from the target behind the reflector, thus requiring only a single lens.

[0016] The optical head provided by this invention is a compact, customizable form that uses a single lens path for both excitation and emission light. The optical head utilizes a mirror and a beam splitter, wherein the beam splitter is positioned to direct the excitation light toward the sample while allowing the emitted light to return through the same lens for detection.

[0017] In this type of optical head, a mirror reflects the excitation beam into the optical path, and a beam splitter divides and guides the light so that the excitation and emission beams share the same path but do not interfere with each other. A single lens is used for both the excitation and emission processes in this type of optical head, resulting in a compact design and reduced complexity.

[0018] Furthermore, such optical heads allow for customizable designs, enabling them to be adapted to a variety of applications, such as different wavelengths, magnifications, or configurations for specialized optical analysis.

[0019] The above general description and the following detailed description are merely examples and not intended to constrain the published text. Other aspects, objectives, and advantages will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. Attached Figure Description

[0020] The benefits and advantages of the embodiments of the present invention will become more apparent to those skilled in the art after reviewing the following detailed description and accompanying drawings, wherein:

[0021] Figure 1 This is a cross-sectional view of an embodiment of the fluorometer optical head based on a publicly available text;

[0022] Figure 2 This is a cross-sectional view of the embodiment of the lens block;

[0023] Figure 3A and Figure 3B This is the bottom view of the bottom block of the lens block. Figure 3A (and top view);

[0024] Figure 4A and Figure 4B This is a top view of the middle block of the lens block. Figure 4A ) and bottom view;

[0025] Figure 5A and Figure 5B This is a top view of the top block of the lens block. Figure 5A ) and bottom view;

[0026] Figure 6 This is a schematic cross-sectional view of a small shape factor optical head;

[0027] Figure 7 An example of a spherical lens used in an optical head is shown. Detailed Implementation

[0028] While the published text allows for various forms of implementation, the preferred implementation is shown in the accompanying drawings and will be described below. It should be understood that the published text should be considered illustrative and is not intended to limit the published text to the specific implementation shown.

[0029] In an embodiment, as will be described below, the optical head of the present invention includes a light source (such as a laser or LED) providing excitation light, a single lens positioned in the optical path that focuses the excitation light onto the sample and collects the emitted light. A beam splitter is positioned above a photodiode and an excitation filter (if desired) and a mirror that reflects the light 90 degrees toward the beam splitter, which in turn reflects the light 90 degrees toward the lens and the sample. In this configuration, the excitation light and the emitted light travel through the same path.

[0030] Now refer to the attached diagram, especially... Figure 1The illustration shows an embodiment of an optical head 10 for use with, for example, a fluorometer, according to the published text. The optical head 10 typically includes a housing 12, a lens block 14, a PCB 16 (on which a photodiode 18 and a light source (such as an LED 20) are mounted), a window 22, a lens 24, and a connector assembly 26. The housing 12 encloses the optical head components. The window 22 (e.g., a fused silica window) is positioned at one end of the housing 12.

[0031] like Figures 2 to 5B As shown, lens block 14 is configured to mount and position laser cleaning or excitation filter 28 and reflector 30, emission filter 32 and dichroic beam splitter 34, as well as lens 24. Lens block 14 is configured to mount components in precise relationships to each other. In the current embodiment, lens block 14 includes a bottom lens block 36, a middle lens block 38, and a top lens block 40. These three lens block segments 36, 38, and 40 are fixed together to form lens block 14.

[0032] refer to Figure 3A and Figure 3B The bottom block 36 of the lens block includes an opening to receive the LED 20 and the photodiode 18. (As...) Figure 4A and Figure 4B As shown, the intermediate block 38 of the lens block is configured to receive the excitation filter 28 and emit the emission filter 32. (As...) Figure 5A and Figure 5B As shown, the top block 40 of the lens block is configured to receive the reflector 30 and the dichroic beam splitter 34. The bottom block 36, the middle block 38, and the top block 40 are assembled with corresponding components and fixed to each other to define the lens block 14. A channel 42 is formed in the lens block to provide an optical path for the beam. The lens block 14 is positioned in the housing 12, adjacent to the window 22.

[0033] A PCB 16, on which photodiode 18 and LED 20 are mounted, is positioned adjacent to the bottom block 36 of the lens block, such that photodiode 18 and LED 20 are positioned in the bottom opening 44 of the lens block. A fluorometer detector 46 extends from the PCB 16 to the opposite end of the housing 12, and pins 48 from the detector 46 terminate at a connector 50, for example, at the end of the housing 12. A mating connector (not shown) (e.g., a 6-pin connector) can be connected to the connector 50 terminating at the end of the detector 46.

[0034] In this embodiment, there are two optical paths 52 and 54 formed by the lens block 14. The first optical path 52 includes an LED 20, an excitation filter 28, and a reflector 30. The second optical path 54 includes a photodiode 18, an emission filter 32, and a dichroic beam splitter 34. In the current embodiment, the excitation filter 28 and the emission filter 32 are single-bandpass filters, and the beam splitter 34 is a single-edge standard epifluorescent dichroic beam splitter.

[0035] A single lens 24 guides the corresponding optical paths 52 and 54 through window 22 into and out of optical head 10. In this embodiment, lens 24 is a targeting plano-convex lens. Because the excitation beam and the emission beam converge or share the same optical path to and from the target after mirror 30, only a single lens 24 is required.

[0036] Advantageously, the optical head 10 of the present invention uses a three-piece lens block 14 assembly, which is assembled into a single unit and includes cavities for the arrangement of the emission filter 32 and excitation filter 28, the aiming plano-convex lens 24, the reflector 30 and the beam splitter 34, as well as optical paths 52, 54, to achieve highly consistent fluorescence measurements across devices. The plano-convex lens 24 enables perfect focusing of the excitation beam.

[0037] A PCB 16 containing LED 20 and photodiode 18 is attached to lens block 14, which ensures the precise alignment of LED 20 and photodiode 18 in the optical path.

[0038] A light source (e.g., LED 20) generates excitation light, which is directed toward a reflector 30. The reflector 30 reflects the light to a beam splitter 34. The beam splitter 34 directs the excitation light through a lens 24 to the sample. The same lens 24 collects the light emitted from the sample, which then passes through the beam splitter 34 back and is directed to a detector for analysis.

[0039] As described above, the optical head 10 of the present invention includes two optical paths—an excitation optical path 52 and an excitation / emission optical path 54. The excitation beam from the LED 20 is redirected at 90° to the beam splitter 34, which guides the excitation beam at 90° to the aiming lens 24. The emission beam is emitted from the target, returns through the lens 24, and reaches the photodiode 18 through the beam splitter 34. Since excitation and emission share the same optical path to and from the target after the reflector 30, the target focus will not suffer from any misalignment that could occur with separate excitation and emission paths.

[0040] Furthermore, since the optical head 10 assembly is a self-contained, self-aligned module with attached LED 20 / photodiode 18 / PCB 16, the application characteristics of the fluorometer can be easily altered by changing the filters 28 and 32. For example, the PTSA-configured optical head can be easily interchanged with the chlorophyll-configured optical head. It is conceivable that this feature can be used by fluorometer users. Moreover, since all optical elements are housed within the optical head assembly 10, these components can be tested before being attached to the rest of the fluorometer, thus streamlining the manufacturing process.

[0041] A novel aspect of the fluorometer optical head assembly of this invention lies in the multi-piece lens block 14 that perfectly aligns the LED 20 and photodiode 18 in the optical path. This structure provides proper alignment of the optical elements during assembly, thereby eliminating tedious alignment operations. In other words, this configuration allows for rapid changes to the optical components while maintaining the integrity of the basic geometric orientation. Furthermore, because the excitation beam and emission beam converge or share the same optical path to and from the target after the reflector 30, only a single lens 24 is required.

[0042] The bottom lens block segment 36, the middle lens block segment 38, and the top lens block segment 40 are each assembled in a specific manner to encapsulate filters 28, 32 and mirror 30, and allow for precise alignment for advanced fluorescence measurements. The dichroic mirror 30, positioned above the emission filter 32, essentially acts as a double-filtering process, allowing for an additional layer of selective screening for fluorescence measurements of the photodiode 18. The incorporation of mirror 30 into this design is also a novel aspect of the optical head 10 of this invention. Mirror 30 is positioned at a 45° angle above LED 20. Optically, this positions LED 20 and photodiode 18 at a 90° angle to each other, which is optimal for fluorescence measurement.

[0043] Those skilled in the art will appreciate the significant advantages over known optical heads. For example, using a single optical path reduces the overall size of the optical head, resulting in a compact design. By utilizing beam splitters and mirrors, the design minimizes optical losses and interference, all of which are provided in a compact and efficient form. The diameter of such optical heads can be as small as approximately 1 / 2” to 3 / 4”, but can be configured in various sizes. The optical head of this invention is customizable and is therefore designed to allow for customization for different wavelengths, sample types, or analytical needs. The compact optical head is also cost-effective because it uses a simplified optical layout, which reduces manufacturing complexity and cost.

[0044] All patents mentioned in this article, whether or not explicitly stated in the published text, are incorporated herein by reference in their entirety.

[0045] In public texts, the words “a” or “a kind” are considered to include both the singular and plural. Conversely, any reference to a plural item should include the singular where appropriate. Furthermore, it should be understood that terms relating to direction or relative orientation, such as, but not limited to, “up,” “down,” “raise,” “lower,” “top,” “bottom,” “above,” “below,” “side,” “left,” and “right,” are used for illustrative purposes and do not limit the scope of the subject matter described herein to such orientations or relative positioning.

[0046] As can be seen from the foregoing, many modifications and variations can be made without departing from the true spirit and scope of the novel concept of the published text. It should be understood that no limitation is intended with respect to the specific embodiments shown, nor should any limitation be inferred from them. The published text is intended to cover all such modifications falling within the scope of the claims by means of the appended claims.

Claims

1. A small form factor optical head that defines a single optical path, comprising: case; A lens, which is positioned on or within the housing; A light source, positioned within the housing, is configured to emit excitation light; A reflector, positioned within the housing, reflects the excitation light to the lens and receives the emitted light returning through the lens; A beam splitter, positioned within the housing, guides the excitation light to the lens and the emitted light; as well as A detector is positioned to receive the emitted light after it has passed through the lens and the beam splitter and returned. The lens, the mirror, and the beam splitter define a single optical path for the excitation and emission light.

2. The optical head according to claim 1, wherein the lens is adjustable.

3. The optical head according to claim 3, wherein the lens is a spherical lens.

4. The optical head according to claim 1, wherein the excitation light is provided by an LED.

5. The optical head according to claim 1, wherein the excitation light is provided by a laser.

6. The optical head according to claim 1 further includes one or more filters.

7. The optical head of claim 6, wherein the one or more filters comprise an emission filter and / or an excitation filter.

8. The optical head according to claim 1 further includes a lens block.

9. The optical head of claim 8, wherein the reflector and the beam splitter are received in a first side of the lens block, and the lens is located in or on a second side of the lens block.

10. The optical head of claim 8, wherein the lens block comprises a first lens block segment configured to receive the light source, a second lens block segment configured to receive one or more filters, and a third lens block segment configured to receive the reflector and the beam splitter.

11. The optical head according to claim 8, wherein the first lens block segment, the second lens block segment and the third lens block segment are fixed to each other and positioned as a unit in the housing.

12. The optical head according to claim 1, wherein the detector is a photodiode.

13. A small form factor optical head that defines a single optical path, comprising: case; lens; The light source is positioned within the housing; A photodiode, which is positioned within the housing; The lens block is positioned within the housing; A reflector, which is positioned within the housing; A first filter and a second filter are positioned within the housing; The lens block is configured to receive the light source, the photodiode, the first filter and the second filter, the reflector and the beam splitter on its first side, and the lens is positioned on the second side of the lens block. The lens is configured to focus the excitation light and allow the emitted light to pass through it. The beam splitter directs the excitation light toward the lens and the emitted light toward the detector.

14. The optical head according to claim 13, wherein the single lens is a spherical lens.

15. The optical head of claim 13, wherein the lens is adjustable.

16. A method for optical analysis, comprising: An optical head is provided, the optical head having: case; A lens, which is positioned on or within the housing; A light source, positioned within the housing, is configured to emit excitation light; a reflector, positioned within the housing, is used to reflect the excitation light to the lens and to receive emitted light returning through the lens. A beam splitter, positioned within the housing, guides the excitation light to the lens and the emitted light; and a detector, which is positioned to receive the emitted light after it has passed through the lens and the beam splitter and returned, wherein the lens, the mirror and the beam splitter define a single optical path for the excitation light and the emitted light; A light beam is emitted from the light source; Receive the transmitted beam; as well as Analyze the emitted beam.

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