TWI923402B - Optical sensing device with composite-wavelength laser source - Google Patents

Abstract

The invention relates to an optical sensing device with composite-wavelength laser source. The optical sensing device includes light-emitting module, a light-guiding module, and an optical processing module. The light-emitting module includes an independent light source configured to emit a single-wavelength light within a wavelength range from 700 nm to 1700 nm. The light-guiding module includes a plurality of optical elements and a plurality of optical fiber units. The light-guiding module is configured to receive the single-wavelength light emitted from the light-emitting module and direct it toward a subject, thereby exciting the subject to generate a plurality of optical signals. The optical processing module includes a spectral analysis unit and a data processing unit, which are configured to receive and analyze the optical signals transmitted from the light-guiding module. The independent light source can be adjusted to selectively emit a single-wavelength light within the specified wavelength range.

Description

Photosensitive device with composite wavelength laser light source

The present invention relates to a photosensitive device with a composite wavelength laser light source, and more particularly to a photosensitive device having a composite wavelength laser light source and suitable for non-invasive blood glucose detection.

Optical sensing devices are widely used in biomedical testing, environmental monitoring, and materials analysis. Their sensing principle primarily involves illuminating the analyte with light of a specific wavelength and analyzing the resulting scattered, absorbed, or fluorescent light to obtain the analyte's optical properties. Among these, Raman spectroscopy, which provides molecular vibrational information and chemical fingerprint characteristics, has been widely used in non-invasive detection, such as blood glucose monitoring or chemical composition identification. However, traditional Raman detection typically uses fixed-wavelength light sources, which cannot be flexibly adjusted according to the needs of different analytes, resulting in limited sensitivity when sensing different depths or complex compositions. Especially when detecting deep tissues or complex samples, traditional systems have difficulty effectively distinguishing Raman scattering signals from background interference, reducing detection accuracy.

However, existing Raman detection technology still faces challenges in modular design and miniaturization when applied to non-invasive detection. Raman spectroscopy systems are mostly laboratory-grade devices, bulky, power-hungry, and expensive, making it difficult to meet the miniaturization and low-power consumption requirements of wearable applications. Furthermore, existing Raman detection systems lack modular design, failing to flexibly provide different light sources or sensing modules to adapt to different sample characteristics, resulting in limited detection sensitivity. Especially in the detection of low-concentration or deep samples, the Raman signal is easily affected by background interference, impacting accuracy and stability. Therefore, a novel Raman detection technology is needed that improves the system's portability, flexibility, and practicality through modular and miniaturized design.

In view of this, the present invention proposes a photosensitive device with a composite wavelength laser light source to improve the problems of insufficient accuracy, low sensing sensitivity and unfavorable miniaturization integration faced by the Raman detection system in non-invasive blood glucose detection applications in the prior art.

The purpose of this invention is to provide a novel photosensitive device using a composite wavelength laser light source, comprising a light emission module, a light guiding module, and an optical processing module. The light emission module can be selected as a near-infrared laser light source or a short-wavelength infrared laser light source with an output wavelength range of 700 nm to 1700 nm. By emitting a single wavelength light within the aforementioned specific wavelength range, and guiding the light to the analyte through multiple optical elements and multiple fiber units in the light guiding module, a corresponding Raman optical signal is generated. The light guiding module then transmits the optical signal to the optical processing module for analysis to obtain the optical characteristics of the target molecules in the analyte. Furthermore, the receiving fiber of this invention is specially designed as a ring-shaped fiber bundle arrangement, and each fiber in the bundle has a different axial offset configuration, enabling it to synchronously receive Raman signals from different tissue depths, effectively enhancing the spatial resolution of the device. Therefore, the photosensitive device of this invention can flexibly select the desired wavelength range for sensing, and integrates optical components such as reflectors, focusing lenses, and dichroic mirrors, as well as optical filter components such as laser filters and long-pass filters in the light guiding module, effectively controlling the light transmission path and signal quality. In summary, the photosensitive device proposed in this invention achieves flexible wavelength modulation through a composite wavelength laser light source. Laser light of different wavelengths can acquire Raman signals at different depths in the analyte, effectively compensating for the energy loss caused by collisions between Raman photons and glucose molecules when using only a single wavelength in deeper tissues, thereby improving the overall signal detection efficiency and depth coverage. The composite wavelength design reduces the need for lens focusing to compensate for energy loss, further simplifying the optical transmission path, facilitating miniaturization of the device, and making it more suitable for wearable applications. Overall, this photosensitive device features high sensitivity, high selectivity, and modularity, making it particularly suitable for non-invasive human blood glucose testing. It provides an accurate, stable, and highly integrated Raman optics detection solution and can also be extended to the analysis of other chemical components.

To achieve the above objectives, the present invention provides a photosensitive device for a composite wavelength laser light source, comprising a light emission module, a light guiding module, and an optical processing module. The light emission module includes an independent light source that provides a single wavelength light ray with a wavelength range between 700 nanometers (nm) and 1700 nanometers (nm). The light guiding module is coupled to the light emission module and includes a plurality of optical elements and a plurality of optical fiber units. The light guiding module receives the single wavelength light ray emitted by the light emission module and guides the single wavelength light ray to a test object to excite the test object to generate multiple optical signals. The optical processing module is coupled to the optical guiding module. The optical processing module includes a spectral analysis unit and a data processing unit for receiving and analyzing the optical signals from the optical guiding module. The independent light source is adjustable to selectively emit a single wavelength of light within the wavelength range. This single wavelength of light is guided to the object under test (DUT) via the optical elements and the fiber unit, and the optical signal is returned from the DUT and then transmitted to the optical processing module.

In one embodiment, the independent light source is a near-infrared (NIR) laser source or a short-wave infrared (SWIR) laser source.

In one embodiment, the light source is a short-wavelength infrared laser source, and emits light of a single wavelength of 1064 nanometers (nm).

In one embodiment, the optical element further includes a plurality of light manipulation elements and a plurality of optical filters, wherein the light manipulation elements are used to adjust the transmission path of the single wavelength light and the optical signal, and the optical filters are used to selectively filter the single wavelength light and the optical signal.

In one embodiment, the light manipulation element is selected from a group consisting of a mirror, a lens, a dichroic mirror, and combinations thereof, and is configured along the transmission path of the single-wavelength light and the optical signal to guide the single-wavelength light to the object under test and collect the optical signal generated by the object under test.

In one embodiment, the optical filter includes a laser optical filter and a long-pass filter, the laser optical filter being disposed between a portion of the optical fiber unit and a portion of the optical control element, and the long-pass filter being disposed between a portion of the optical control element.

In one embodiment, the optical fiber unit further includes a transmitting optical fiber and a receiving optical fiber, the optical transmitting module being coupled to the optical guiding module via the transmitting optical fiber, and the optical guiding module being coupled to the optical processing module via the receiving optical fiber.

In one embodiment, the receiving fiber is a ring-shaped fiber bundle structure containing fibers arranged with different offsets to collect optical signals from different depths and direct them to the optical processing module.

In one embodiment, the spectral analysis unit includes a spectrometer and a detector, the spectrometer being coupled to the receiving fiber to receive the optical signal, and the detector being coupled to the spectrometer to convert the optical signal into a complex electrical signal.

In one embodiment, the data processing unit is a computer system used to receive and process the electrical signal.

After referring to the figures and the embodiments described thereafter, those skilled in the art will understand the other purposes of the invention, as well as the technical means and embodiments of the invention.

The present invention will be explained through embodiments below. These embodiments are not intended to limit the implementation of the invention to any specific environment, application, or particular method as described in the embodiments. Therefore, the description of the embodiments is for illustrative purposes only and is not intended to limit the invention. It should be noted that in the following embodiments and drawings, devices not directly related to the present invention have been omitted and are not shown, and the dimensional relationships between the devices in the drawings are for ease of understanding only and are not intended to limit the actual scale.

Please refer to Figure 1. An embodiment of the present invention, a photosensitive device 1000 of a composite wavelength laser light source, includes a light emitting module 1, a light guiding module 2, and an optical processing module 3. The light emitting module 1 is coupled to the light guiding module 2, and the light guiding module 2 is in turn coupled to the optical processing module 3. In other words, the light emitting module 1, the light guiding module 2, and the optical processing module 3 are coupled sequentially.

Referring also to Figure 2, the light emission module 1 includes an independent light source 11, which serves as the light emission source for the light emission module 1 and can selectively emit a single wavelength light with a wavelength range between 700 nanometers (nm) and 1700 nanometers (nm). In one embodiment, the independent light source 11 can be a near-infrared (NIR) laser source of 700 nm to 1000 nm, or a short-wave infrared (SWIR) laser source of 1000 nm to 1700 nm. In one embodiment, the independent light source 11 can be a surface-emitting laser source or an edge-emitting laser source. In a preferred embodiment, the independent light source 11 can be a short-wavelength infrared laser light source emitting a wavelength of approximately 1064 nanometers. It possesses excellent tissue penetration capabilities, allowing sensing depths down to the dermis. This effectively excites Raman signals generated by target molecules at different depths (such as the epidermis, dermis, and their junctions), thereby obtaining spectral information with higher resolution and accuracy. By flexibly adjusting the wavelength selection according to the detection conditions and molecular characteristics of the analyte, the user can achieve optimized light penetration and sensing sensitivity.

The light guiding module 2 includes a plurality of optical elements 21 and a plurality of fiber units 22. The light guiding module 2 can receive a single-wavelength light emitted by the light emitting module 1 and guide the single-wavelength light to a test object to excite the test object to generate corresponding multiple optical signals. The optical signals are mainly scattered light signals from different depth regions of the test object, including Rayleigh scattering and Raman scattering components. In detail, after the single-wavelength light is emitted from the light emitting module 1, it is transmitted through some of the fiber units 22 to some of the optical elements 21, further focusing the single-wavelength light and illuminating the test object. Then, some of the optical elements 21 collect the optical signals generated after the test object is illuminated and transmit them through another fiber unit 22 to the optical processing module 3 for signal analysis. The optical element 21 further includes a plurality of light manipulation elements 211 and a plurality of optical filters 212. The light manipulation elements 211 are used to adjust the optical path direction and transmission path of a single wavelength light and the optical signal. The optical filters 212 are used to selectively filter the single wavelength light and the optical signal. The light manipulation element 211 may include a mirror 2111, a lens 2112, and a dichroic mirror 2113, or any combination thereof, and is configured along the transmission path of the single wavelength light and the optical signal. The light manipulation element 211 is mainly used to accurately guide the single wavelength light to the position of the object under test, and effectively collect and guide the optical signal reflected or scattered by the object under test back. In this embodiment, the light control element 211 of the present invention is actually configured as three mirrors 2111, two lenses 2112 and one dichroic mirror 2113. The number and position of these components can be adjusted according to the wavelength of the selected light source and the actual optical path design requirements, and are not limited here.

The optical filter 212 includes a laser filter 2121 and a long-pass filter 2122. The laser filter 2121 is disposed in the optical path to selectively filter out laser background light of non-target wavelengths, allowing only a single wavelength of light emitted by the independent light source 11 to pass through, thereby ensuring the wavelength purity of the incident light and effectively reducing stray light interference. The laser filter 2121 is disposed between a portion of the optical fiber unit 22 and a portion of the optical manipulation element 211. The long-pass filter 2122 is also disposed in the optical path, between some of the optical manipulation elements 211, to selectively pass the optical signal with a wavelength higher than a preset threshold, while blocking Rayleigh scattered light with the same wavelength as the incident light, so as to improve the overall signal-to-noise ratio and thereby enhance the accuracy and stability of subsequent optical analysis.

The optical fiber unit 22 further includes a transmitting optical fiber 221 and a receiving optical fiber 222. The optical transmitting module 1 is coupled to the optical guiding module 2 via the transmitting optical fiber 221, and the optical guiding module 2 is coupled to the optical processing module 3 via the receiving optical fiber 222. It should be noted that the receiving optical fiber 222 is a ring-shaped optical fiber bundle structure (not shown in the figure), which is composed of multiple optical fibers arranged with different lateral offsets, and can simultaneously receive the optical signals scattered from different depth regions of the test object. Specifically, at the end connected to the optical guiding module 2, the ring-shaped optical fiber bundle is arranged in a concentric ring form, with each ring corresponding to a different lateral offset on the sample surface. Offset is defined as the radial distance between different fibers on the receiver fiber 222 relative to the central axis of the laser beam, measured in micrometers, and corresponds to different skin detection depths. For example, the innermost ring has a lateral offset of 0 micrometers, the second ring has 50 micrometers, the third ring has 100 micrometers, the fourth ring has 150 micrometers, and the outermost ring has 200 micrometers. Because the outer ring fibers have a larger offset, the received signal strength is relatively weaker. Therefore, more fibers are arranged on the rings with larger offsets to compensate for signal attenuation. Conversely, the signal strength is stronger in the innermost rings, with less offset, and the number of fibers required gradually decreases. By employing this concentric ring arrangement, the optical fiber bundles can receive scattered Raman optical signals from the epidermis, dermis, and even deeper tissues. The multi-layered ring structure allows for the simultaneous capture of both shallow and deep signals, further enhancing the depth resolution and detection accuracy of the photosensitive device in complex biological tissues. Furthermore, the other end is linearly grouped and aligned based on the spatial offset of each fiber. This design clearly distinguishes scattered optical signals from different depth regions and effectively guides them to the optical processing module 3 for subsequent wavelength analysis. It should be noted that the number and offset of the optical fibers arranged in the ring optical fiber bundle structure of the receiving optical fiber 222 can be adjusted according to the actual use of laser light source and different optical path configurations, and are not limited here.

The optical processing module 3 includes a spectral analysis unit 31 and a data processing unit 32 for receiving and analyzing the optical signals from the optical guiding module 2. The spectral analysis unit 31 includes a spectrometer 311 and a detector 312. The spectrometer 311 is coupled to the receiving fiber optic cable 222 to receive the optical signals transmitted from the optical guiding module 2 and perform spectral analysis to obtain the Raman spectral information of the signal. The detector 312 is connected to the spectrometer 311 to convert the analyzed optical signals into corresponding complex electrical signals. The spectrometer 311 can be a near-infrared spectrometer, a short-wavelength infrared spectrometer, or a spectrometer covering a wide wavelength range of NIR and SWIR bands, such as a system using an indium gallium arsenide (InGaAs) detector. The detector 312 can be a charge-coupled device (CCD) to detect the resolved optical signal with high sensitivity and output an electrical signal for further processing by the data processing unit 32.

In this embodiment, the module configuration and operation flow of the photosensitive device 1000 of the composite wavelength laser light source of the present invention are as follows. The light emitting module 1 is coupled to one end of the emitting fiber 221 to guide the single-wavelength light emitted by the independent light source 11. The other end of the emitting fiber 221 is connected to the laser optical filter 2121, which transmits the single-wavelength light emitted by the independent light source 11 to the light guiding module 2. Then, the single-wavelength light enters the laser optical filter 2121 for laser light filtering to ensure that the light entering the subsequent optical path is a single-wavelength light of a specific wavelength. After passing through the laser filter 2121, the light is reflected and its path is adjusted by a series of mirrors 2111 arranged in sequence. The angle of the mirrors is used to precisely guide the light path. Then, a single-wavelength light enters the dichroic mirror 2113, which selectively reflects that specific wavelength of light. This reflected light is then transmitted to a lens 2112, which focuses the single-wavelength light onto the object under test. The optical signal generated when the object under test is excited is collected again by the same lens 2112 and returns to the dichroic mirror 2113 via the original light path. Since the wavelength of the scattered light from the optical signal differs from the original incident light, the dichroic mirror 2113 allows its transmission, guiding it to the sequentially arranged long-pass filters 2122. These filters block unwanted noise components such as Rayleigh scattering, allowing only optical signals with wavelengths higher than a preset threshold to pass through. The filtered optical signal is then focused and shaped by another lens 2112 before entering the receiving fiber optic cable 222. The receiving fiber optic cable 222 guides the optical signal to the optical processing module 3 for subsequent spectral analysis and signal interpretation to complete the overall optical sensing operation.

In this embodiment, the analyte is human tissue or biological tissue. The photosensitive device of this invention is used to detect blood glucose in human tissue as the target molecule.

In addition, in this embodiment, the data processing unit 32 is a computer system used to receive and process the electrical signals. Furthermore, the computer system also has control functions to control the operation of the light emission module 1, the light guiding module 2, and the optical processing module 3. The computer system can also execute software to control the laser light source, the spectrometer, and the data collection process, and use a spectral analysis model to analyze the acquired Raman spectral information to calculate the blood glucose concentration of the analyte.

The photosensitive device using a composite wavelength laser light source of this invention has advantages such as non-invasive detection, selectable composite wavelength, and modular design. The photosensitive device includes independent light sources that can be selected from near-infrared laser sources with wavelengths ranging from 700 nm to 1700 nm, and short-wavelength infrared laser sources. By providing single-wavelength laser light from independent light sources and selecting an appropriate wavelength according to the required tissue depth, the device integrates data obtained from different wavelengths to improve the separation efficiency of Raman signals and the detection accuracy of deep signals. Furthermore, the optical fiber unit of this photosensitive device further includes a ring-shaped optical fiber bundle structure, in which the optical fibers are arranged according to different spatial offsets to overcome the energy loss and signal collection difficulties caused by frequency displacement of Raman photons in deep tissues, thereby improving the collection efficiency of Raman scattering signals of blood glucose molecules located below the junction of the epidermis and dermis. The photosensitive device of this invention is applied to non-invasive blood glucose detection. Through the selection of composite light sources and modular design, the required lens optical path can be reduced, realizing a miniaturized structure. Furthermore, through efficient integration and low power consumption design, the portability and practicality of wearable devices are improved.

The above embodiments are merely illustrative of the embodiments of the present invention and to explain the technical features of the present invention, and are not intended to limit the scope of protection of the present invention. Any modifications or equivalent arrangements that can be easily made by those skilled in the art are within the scope claimed by the present invention, and the scope of protection of the present invention shall be determined by the scope of the patent application.

1000: Photosensitive device for composite wavelength laser light source; 1: Light emission module; 11: Independent light source; 2: Light guiding module; 21: Optical element; 211: Light control element; 2111: Mirror; 2112: Lens; 2113: Dichroic mirror; 212: Optical filter; 2121: Laser optical filter; 2122: Long-pass filter; 22: Fiber unit; 221: Transmitting fiber; 222: Receiving fiber; 3: Optical processing module; 31: Spectroscopic analysis unit; 311: Spectrometer; 312: Detector; 32: Data processing unit.

Figure 1 is a schematic diagram of the structure of the photosensitive device of the complex wavelength light source of the present invention; and Figure 2 is a schematic diagram of the specific structure of the photosensitive device of the complex wavelength light source of the present invention.

1000: Photosensitive device using a composite wavelength laser light source

1: Light emission module

11: Independent light source

2: Optical Guidance Module

21: Optical Components

211: Light control element

2111: Mirror

2112: Lens

2113: Dichroic mirror

212: Optical Filters

2121: Laser Optical Filter

2122: Long-pass filter

22: Optical Fiber Unit

221: Transmitter fiber

222: Receiver fiber

3: Optical Processing Module

31: Spectral Analysis Unit

311: Optical Spectrometer

312: Detector

32: Data Processing Unit

Claims (9)

A photosensitive device using a composite wavelength laser light source includes: a light emitting module comprising an independent light source providing a single wavelength light ray with a wavelength range between 700 nanometers (nm) and 1700 nanometers (nm); a light guiding module coupled to the light emitting module, the light guiding module comprising a plurality of optical elements and a plurality of optical fiber units, the light guiding module receiving the single wavelength light ray emitted by the light emitting module and guiding the single wavelength light ray to a test object to excite the test object to generate a plurality of optical signals, the optical fiber unit further comprising a transmitting optical fiber and a receiving optical fiber; and An optical processing module is coupled to the optical guiding module. The optical processing module includes a spectral analysis unit and a data processing unit for receiving and analyzing the optical signal from the optical guiding module. The optical emitting module is coupled to the optical guiding module via a transmitting fiber, and the optical guiding module is coupled to the optical processing module via a receiving fiber. The independent light source is adjustable to selectively emit a single wavelength light within the wavelength range. The single wavelength light is guided to the object under test via the optical element and the fiber unit, and the optical signal is returned from the object under test and then transmitted to the optical processing module. The photosensitive device for a composite wavelength laser light source as described in claim 1, wherein the independent light source is a near-infrared (NIR) laser light source or a short-wavelength infrared (SWIR) laser light source. The photosensitive device of the composite wavelength laser light source as described in claim 2, wherein the independent light source is a short-wavelength infrared laser light source and emits a single wavelength light with a wavelength of 1064 nanometers (nm). The photosensitive device for a composite wavelength laser light source as described in claim 1, wherein the optical element further includes a plurality of light manipulation elements and a plurality of optical filters, the light manipulation elements being used to adjust the transmission path of the single wavelength light and the optical signal, and the optical filters being used to selectively filter the single wavelength light and the optical signal. As described in claim 4, in the photosensitive measuring device of the composite wavelength laser light source, the light control element is selected from a group consisting of a mirror, a lens, a dichroic mirror and combinations thereof, and is configured along the transmission path of the single wavelength light and the optical signal to guide the single wavelength light to the object under test and collect the optical signal generated by the object under test. The photosensitive device for a composite wavelength laser light source as described in claim 5, wherein the optical filter includes a laser optical filter and a long-pass filter, the laser optical filter being disposed between a portion of the optical fiber unit and a portion of the optical control element, and the long-pass filter being disposed between a portion of the optical control element. The photosensitive device of the composite wavelength laser light source as described in claim 1, wherein the receiving fiber is a ring-shaped fiber bundle structure and includes fibers arranged with different offsets, for collecting optical signals from different depths and directing them to the optical processing module. The photosensitive device for a composite wavelength laser light source as described in claim 1, wherein the spectral analysis unit includes a spectrometer and a detector, the spectrometer being coupled to the receiving fiber to receive the optical signal, and the detector being coupled to the spectrometer to convert the optical signal into a complex electrical signal. The photosensitive device for a composite wavelength laser light source as described in claim 8, wherein the data processing unit is a computer system for receiving and processing the electrical signal.