Optical sensor device

Abstract

The invention achieves an optical sensor device (1) comprising: a laser light source (2) for providing laser light (L); an optical ring resonator (3) arranged to receive a portion of the laser light via a coupler (4), wherein the ring resonator (3) has an optically nonlinear material and / or an optically absorbing material such that a resonance curve (31) of the ring resonator (3) is asymmetric about a resonance wavelength (32) as a function of a wavelength of the laser light (L) to be received, wherein the resonance curve (31) has a side (31a) that rises gently relative to the resonance wavelength and a side (31b) that rises steeply relative to the resonance wavelength (32); a detection device (5) arranged to detect a portion of the laser light (L) that is not coupled into the ring resonator (3); a control device (6) designed to control a laser power of the laser light source (2) based on the detected portion of the laser light (L) that is not coupled into the ring resonator (3) such that laser light (L) coupled into the ring resonator (3) has a laser wavelength (30) arranged on the steeply rising side (31b) of the resonance curve (31).

Description

Technical Field

[0001] This invention relates to an optical sensor device. Background Technology

[0002] Optical gyroscopes are typically based on the Sagnac effect. There are fiber-optic gyroscopes and ring laser-based gyroscopes. Fiber-optic gyroscopes are based on the principle that light propagates continuously in two opposite directions within a glass fiber. Due to the Sagnac effect, the effective propagation lengths of the two optical paths change as the gyroscope rotates. This causes a phase shift in the light. After passing through the glass fiber, the two optical paths meet again and the light waves superimpose. This results in both constructive and destructive interference, producing light waves whose intensity changes proportionally to the rotation speed.

[0003] In a ring laser gyroscope, light propagates within a ring resonator. The ring resonator is a closed circular structure within which light can circulate. Specific modes can exist within the ring resonator, interfering with each other due to the interference of light after it has circled the ring once. Thus, certain frequencies are amplified while others are attenuated within the ring resonator. Furthermore, as the system rotates, the effective optical path also changes due to the Sagnac effect, and consequently, the resonant frequency of the resonator changes. This results in the transmitted intensity varying with the rotational speed during rotation.

[0004] For compact, chip-integrated fiber-optic and ring-resonator-based gyroscopes, very high-quality manufacturing processes are required to achieve sensitivity comparable to larger products. A particular challenge lies in fabricating a very steep resonance profile for the ring resonator, thereby improving sensitivity.

[0005] Feng et al.'s paper, "Progress of Waveguide Ring Resonators Used in Micro-Optical Gyroscopes," published in Photonics, 7, 96 (2020), describes optical gyroscopes.

[0006] Therefore, the object of the present invention is to provide an improved optical sensor device that achieves enhanced sensitivity and / or compactness. Summary of the Invention

[0007] The present invention provides an optical sensor device according to claim 1.

[0008] Preferred extensions are the subject of the dependent claims.

[0009] Advantages of the present invention According to the present invention, an optical sensor device includes: a laser source for providing laser light; an optical ring resonator arranged to receive a portion of the laser light via a coupler, wherein the ring resonator has an optically nonlinear material and / or an optically absorbing material such that the resonance curve of the ring resonator as a function of the wavelength of the laser light to be received is asymmetrical about the resonant wavelength, wherein the resonance curve has a side that rises gently relative to the resonant wavelength and a side that rises steeply relative to the resonant wavelength; a detection device configured to detect a portion of the laser light not coupled into the ring resonator; and a control device designed to control the laser power of the laser source based on the detected portion of the laser light not coupled into the ring resonator, such that the laser light coupled into the ring resonator has a laser wavelength arranged on the steeply rising side of the resonance curve.

[0010] This invention is based on a compact sensor structure that utilizes the nonlinearity of optical materials to increase the steepness of the resonance and thereby improve sensitivity. This allows for a compact, optically integrated, chip-based rotational rate sensor that does not require extremely high manufacturing quality.

[0011] To achieve a steep resonance curve, at least one optically nonlinear medium and / or an optically strongly absorbing medium, or a combination thereof, is used. Furthermore, an architecture is employed to tune the laser power and optionally the laser phase. Importantly for the medium, it must either possess a high second- or third-order polarizability or have associated absorption capabilities to preferably produce an optically stable state. Here, the medium can also have artificially created defects to enhance light absorption. An example is unbonded silicon atoms in a silicon nitride waveguide. Two-photon absorption can occur at silicon atoms, an absorption that does not occur in a silicon nitride waveguide, thereby generating additional heating of the waveguide. In conjunction with this, a system consisting of detector and laser power control, optionally also phase control, is used to tune the power in the resonator; this system also influences the bistable state.

[0012] Laser light from a laser source is coupled into a ring resonator via a coupler. Field enhancement and thus high intensity are typically generated in this resonator. The resonator contains arbitrary optical nonlinear or optically absorbing materials, either in the form of waveguides, such as on an integrated photonic chip, or within a free-space resonator. For nonlinearity, any material with a relevant second-order polarizability, such as lithium niobate (including PPLN), or with a relevant third-order polarizability, such as silicon or silicon nitride, is suitable. Regarding absorption, both the material itself and the manufacturing process play a decisive role. Depending on the orientation and layering of the crystals during semiconductor manufacturing, as well as the quality of the manufacturing process, they absorb more or fewer photons.

[0013] The transmittance of a ring resonator, or coupler, i.e., the portion of the laser light not coupled into the ring resonator, can be calculated from the coupling ratio κ, loss rate γ, and detuning Δ. All three define intensity amplification, but detuning causes an optical bistable state and a shift in the resonant frequency. This shift is composed of effects such as self-phase modulation and thermal modulation. Self-phase modulation induces bistable states based on polarizability, while thermal modulation causes photons to be absorbed and converted into heat. Both induce bistable states, which, when plotted as a function of wavelength, result in an asymmetric resonance curve. The slope of one nonlinear or steep side of the curve is steeper than the opposite side, with the two sides separated by the resonant wavelength, i.e., the highest point of the resonance curve.

[0014] As described above, in this invention, the transmitted power of the ring resonator, i.e., the portion of the laser uncoupled into the ring resonator, is measured. For this purpose, it is preferable to shift the resonant frequency of the ring resonator so that the laser wavelength is positioned at its steepest point. This can be achieved by adjusting the laser wavelength accordingly. Therefore, with the laser wavelength and laser power being constantly adjusted, it is advantageous to adjust the resonant frequency of the ring resonator. Optionally, this can be additionally or alternatively achieved by a phase shifter, which can be adjusted according to the laser power, as further described below. Strong signal edges and thus high sensitivity can be achieved through nonlinearity. If the rotation rate is applied to the system, a change in the effective length of the resonator occurs due to the Sagnac effect, resulting in a change in the resonant frequency and thus an effective phase change. Due to this change, the measured transmitted power changes.

[0015] Because of the bistable state, the change in transmittance becomes more significant, thus making the sensor system more sensitive. This is also feasible because the steady state is established very rapidly in this optical system, so the phase change can be measured almost directly as a change in power.

[0016] According to a preferred embodiment of the optical sensor device, a beam splitter is provided, arranged and configured to split a laser beam into a first optical path and a second optical path by a predetermined ratio. Thus, the original optical path from the laser source to the coupler is split into the first and second optical paths. The coupler to the ring resonator is arranged in the first optical path. A detection device is configured to detect the laser beam split in the second optical path. This can be achieved by using a detector, such as a photodetector, to measure the portion of the laser beam deflected into the second optical path. Thus, for example, the temperature or current of the laser can be adjusted so that the power measured in the second optical path remains constant.

[0017] According to a preferred embodiment of the optical sensor device, an optical switch is provided, configured to deflect a laser beam into a first or second optical path. In this embodiment, a coupler is also arranged in the first optical path. A detection device is configured to detect the laser beam deflected into the second optical path. This can be achieved by a (photodetector) measuring the portion of the laser power deflected into the second optical path by the optical switch, and adjusting the temperature or current of the laser, for example, so that the measured power remains constant. The switching time of the optical switch from the first optical path to the second optical path and vice versa is preferably in the microsecond range. This is significant because the settling time of the ring resonator is in the nanosecond range, and therefore faster than the switching time of the optical switch. The optical switch can be integrated into the coupler, in particular. This requires only a single optical path.

[0018] According to a preferred embodiment of the optical sensor device, the wavelength is positioned at the steepest point of the resonance curve. This can be controlled either by the laser source itself or by a phase shifter, as further described below. This arrangement causes a change in the optical path length, thereby maximizing the variation in the resonance characteristics at the wavelength used. This improves the sensitivity of the optical sensor device.

[0019] According to a preferred embodiment of the optical sensor device, the ring resonator has a phase shifter configured to shift the phase of a laser coupled to the ring resonator. The phase shifter can be a thermal phase shifter, which shifts the phase by temperature, or an electro-optic phase shifter, which shifts the phase by the refractive index of the waveguide material. By appropriately controlling the laser phase, the frequency or wavelength of the laser can be changed, particularly related to the laser power, so that the wavelength used is optimally tuned to the steepest position of the resonance curve, thereby achieving improved sensitivity.

[0020] According to a preferred embodiment of the optical sensor device, a temperature sensor is provided for detecting ambient temperature. The control device is designed to control the phase shifter based on the detected ambient temperature. The phase can be shifted accordingly based on the measured value, so that the operating point is preferably always at the edge of the steepest transmittance. This compensates for temperature fluctuations, allowing the sensitivity of the optical sensor device to be maintained even when the ambient temperature fluctuates.

[0021] According to a preferred embodiment of the optical sensor device, a variable attenuator is provided, disposed between the laser source and the coupler. This allows for the adjustment of laser power using an additional attenuation element in the form of a variable attenuator. This is more stable than temperature or current regulation, as the latter two can also alter the wavelength. The variable attenuator can be integrated into a chip between the laser source and the coupler. A control device is configured to manipulate the variable attenuator to control the laser power. Furthermore, the detector can serve as a reference sensor to correctly interpret power variations on other detectors. This detector can be implemented in a chip-integrated manner, for example, after the coupler, such as via a graphene-based photoresistor, or macroscopically disposed after the laser source.

[0022] According to a preferred embodiment of the optical sensor device, the detection device is configured to detect laser light coupled out from a ring resonator via another coupler. The control device is designed to control the laser power based on the detected amount of light coupled out from the ring resonator. This provides additional adjustment for the optical power in the resonator. Reliable operation can be guaranteed because the nonlinearity depends on the power in the resonator. For this purpose, a portion of the power in the resonator can be coupled out and detected. The laser source can then be post-tuned so that the power in the resonator remains constant. Thus, a defined portion of the light in the resonator can be coupled out and measured through another coupling point. Advantageously, this other coupler is designed to be broadband, thereby coupling out the same proportion of optical power in the resonator regardless of wavelength.

[0023] According to a preferred embodiment of the optical sensor device, the control device is designed to control the phase shifter based on the detected amount of light from the laser coupled out of the ring resonator. This allows for the adaptation of the wavelength of the laser coupled to the ring resonator or the resonant conditions of the ring resonator to a separate phase shifter, thereby ensuring high sensitivity.

[0024] According to a preferred embodiment of the optical sensor device, the ring resonator has a slot waveguide with a slot region located between a first conductor core and a second conductor core, wherein an optically nonlinear material and / or an optically absorbing material is disposed in the slot region. This allows the material to possess higher nonlinearity. Simultaneously, other waveguides can have different shapes to realize a sensitive sensing region within the ring resonator, while simultaneously achieving efficient light guiding in the remaining optical path.

[0025] According to a preferred embodiment of the optical sensor device, a ring resonator is arranged on a photonic integrated circuit. Furthermore, a chip coupler is provided, designed to couple laser light provided by a laser source to the photonic integrated circuit. This achieves a particularly compact structure.

[0026] According to a preferred embodiment of the optical sensor device, the ring resonator and the laser source are heterogeneously or homogeneously integrated on a photonic integrated circuit. This achieves a particularly compact structure without requiring a chip coupler.

[0027] According to a preferred embodiment of the optical sensor device, the coupler is constructed as an evanescent wave coupler or a multimode interferometer. These couplers can be integrated on a chip basis, thus ensuring compactness. Furthermore, they represent particularly reliable optical components.

[0028] According to a preferred embodiment of the optical sensor device, the ring resonator and coupler are implemented through an arrangement of a beam splitter and a free-space mirror. This allows the optical sensor device to be implemented using simple and relatively inexpensive components.

[0029] According to a preferred embodiment of the optical sensor device, the ring resonator has a horse-race shape (similar to an elongated aperture shape) or a spiral arrangement. Thus, the ring resonator has an extended sensing area, thereby improving sensitivity due to the larger area. Attached Figure Description

[0030] The present invention will now be described in detail with reference to the embodiments illustrated in the accompanying drawings.

[0031] The attached diagram shows: Figure 1A A schematic illustration of an optical sensor device according to an embodiment of the present invention is shown; Figure 1B A schematic diagram illustrating the resonance curve of a ring resonator in an optical sensor device according to an embodiment of the present invention; Figure 2 A schematic illustration of an optical sensor device according to another embodiment of the present invention is shown; Figure 3 A schematic illustration of an optical sensor device according to another embodiment of the present invention is shown; Figure 4 A schematic illustration of an optical sensor device according to another embodiment of the present invention is shown; Detailed Implementation

[0032] In the accompanying drawings, the same reference numerals denote the same or functionally identical elements.

[0033] Figure 1A A schematic illustration of an optical sensor device 1 according to an embodiment of the present invention is shown.

[0034] The optical sensor device 1 shown in Figure 1 includes a laser source 2 for providing laser light L. The laser source 2 can be any type of laser suitable for this application. A compact laser source 2 is preferred, which also has a narrow linewidth and a low mode count, and preferably oscillates in a single mode. For example, a DFB laser or a diode-pumped fiber laser with a Bragg grating can be used.

[0035] Furthermore, the optical sensor device 1 includes an optical ring resonator 3 arranged to receive a portion of the laser light via a coupler 4. In some embodiments, the coupler 4 is configured as an evanescent wave coupler. In other embodiments, the coupler 4 is configured as a multimode interferometer. The ring resonator 3 has an optically nonlinear material and / or an optically absorbing material, such that the resonance curve 31 of the ring resonator 3 as a function of the wavelength of the laser light L to be received is asymmetric about the resonant wavelength 32; a detection device 5 is configured to detect the portion of the laser light L that is not coupled into the ring resonator 3. A photodetector 5 is thus provided to detect the laser light L that is not coupled into the ring resonator but passes through the coupler. The transmittance of the ring resonator 3, i.e., the portion of the laser light L that is not coupled into the ring resonator, can be expressed as... The formula includes coupling ratio κ, loss rate γ, and detuning Δ. The transmitted laser L is detected by photodetector 5.

[0036] The optical sensor device 1 also includes a control device 6 designed to control the laser power of the laser source 2 based on the portion of the detected laser L that is not coupled to the ring resonator 3, such that the laser L coupled to the ring resonator has a laser wavelength that is positioned on the steeply rising side 31b of the resonance curve 31. The resonance curve 31 with the steeply rising side 31b will be described below. Figure 1B Detailed explanation follows.

[0037] Figure 1B A schematic diagram of the resonance curve 31 of the ring resonator 3 in an optical sensor device according to an embodiment of the present invention is shown.

[0038] Figure 1B The resonance curve 31 shown is plotted with the intensity on the vertical axis 33 as a function of the wavelength 34. The resonance curve 31 has a side 31a that rises gently relative to the resonant wavelength 32 (which represents the highest point of the resonance curve 31) and a side 31b that rises steeply relative to the resonant wavelength 32. In this embodiment of the optical sensor device 1, the wavelength 30 of the laser L coupled to the ring resonator 3 is arranged at the steepest point of the resonance curve 31.

[0039] Coupling rate and loss rate define the intensity amplification of the resonance curve 31. Detuning results in optical bistable states and a shift in the resonant frequency. This shift is composed of effects such as self-phase modulation and thermal modulation. Self-phase modulation induces bistable states due to polarizability, while thermal modulation causes photons to be absorbed and converted into heat. Both induce bistable states, such as... Figure 1B As shown. It can be seen that the slope of the nonlinear resonance curve 31, especially on the steeply rising side 31b, is steeper than the linear curve 33 plotted for comparison, which represents the symmetrical resonance curve 35 when there is no optical nonlinearity and / or optical absorbing material in the ring resonator 3. In this invention, the power of the laser L transmitted by the ring resonator 3 is measured by the photodetector 5. For this purpose, the resonant frequency or resonant wavelength 32 of the ring resonator 3 is shifted so that the wavelength 30 of the coupled laser is positioned as steeply as possible, such as... Figure 1B As shown.

[0040] By employing nonlinearity, strong signal edges can be achieved, thereby enabling high sensitivity. If a rotational rate is applied to the system, the effective length of the resonator changes due to the Sagnac effect, resulting in a change in the resonant frequency (32 Hz) and thus an effective phase change. Due to this change, Figure 1A The transmitted power measured at point 5 of the photodetector changes. Due to the bistable state, the change in transmittance becomes more significant, thus making optical sensor device 1 more sensitive. This is also feasible because the steady state is established very rapidly in this optical system, so the phase change can be measured almost directly as a power change.

[0041] Figure 2 A schematic illustration of an optical sensor device 1 according to another embodiment of the present invention is shown.

[0042] Figure 2 The optical sensor device 1 is based on the optical sensor device 1 of Figure 1, and they can be combined with each other.

[0043] Figure 2 The optical sensor device 1 shown has a beam splitter 71, which is arranged and configured to split the laser L into a first optical path 11 and a second optical path 12 at a predetermined ratio. A coupler 4 is arranged on the first optical path 11. A detection device 5 is configured to detect the laser L split into the second optical path. This means that, in addition to the first photodetector 5a (which detects the laser not coupled to the ring resonator 3 in the first optical path 11), a second photodetector 5b is also provided, which detects the laser split into the second optical path 12. The second photodetector 5b is connected to the control device 6 (for clarity, in...). Figure 2 (omitted) connection, and configured to control the laser power of laser source 2 based on the amount of light measured at the second photodetector 5b.

[0044] Figure 3 A schematic illustration of an optical sensor device 1 according to another embodiment of the present invention is shown.

[0045] Figure 3 The optical sensor device 1 is based on the optical sensor device 1 of Figure 1, and they can be combined with each other. Furthermore, Figure 3 The optical sensor device shown can be considered as Figure 2 An alternative configuration to optical sensor device 1. However, Figure 2 and Figure 3 The optical sensor devices shown can still be combined with each other.

[0046] Figure 3 The optical sensor device 1 shown has an optical switch 72 configured to deflect a laser beam into a first optical path or a second optical path. Unlike the beam splitter 71, the optical switch 72 deflects the entire amount of incident laser light L from the laser source 2 into the first or second optical path.

[0047] The detection device 5 is configured to detect laser light deflected into the second optical path. For this purpose, the two optical paths 11 and 12 are combined into a single photodetector 5, which detects either the laser light L propagating in the first optical path 11 that has not been coupled to the ring resonator 3 by the coupler 4, or the laser light L propagating in the second optical path 12, depending on the switching state of the optical switch 72. The photodetector 5 and the control device 6 (for clarity) are... Figure 2 (The text is omitted here.) The optical switch 72 is connected and configured to control the laser power of the laser source 2 based on the amount of light measured at the photodetector 5, according to the setting of the optical switch. Since the settling time of the ring resonator 3 is in the nanosecond range, the optical switch 72 can switch in the microsecond range to monitor the power of the laser source 2 and adapt accordingly.

[0048] Alternatively, the beam splitter 71 or the optical switch 72 can also be implemented in the coupler 4. In this way, only one coupler 4 is needed as a component, and only one optical path is needed to the photodiode 5.

[0049] Figure 4 A schematic illustration of an optical sensor device 1 according to another embodiment of the present invention is shown.

[0050] Figure 4 The optical sensor device 1 is based on Figure 1 to Figure 3 The optical sensor device 1, and can also be combined with these.

[0051] In this embodiment, the ring resonator has a phase shifter 80 configured to shift the phase of the laser L coupled to the ring resonator 3. The phase shifter 80 can be a thermal phase shifter 80, which shifts the phase by temperature, or an electro-optic phase shifter, which shifts the phase by the refractive index of the waveguide material. By appropriately controlling the phase of the laser L, the frequency or wavelength of the laser L can be changed so that the wavelength is optimally tuned to the steepest point of the resonance curve 31, thereby achieving improved sensitivity. Furthermore, another phase shifter 81 is arranged between the beam splitter 71 (or, in some embodiments, an optical switch 72) and the coupler 4, and is manipulated by the control device 6. The laser L can also be phase-shifted and thus frequency-shifted to tune the wavelength of the laser to the steepest point of the resonance curve 31 of the ring resonator 3 (the connection between the control device 6 and the phase shifter 81 is...). Figure 4 (Not shown in the image for clarity).

[0052] In addition, the optical sensor device 1 has a temperature sensor 82 for detecting ambient temperature. The control device 6 is designed to control the phase shifter 80 based on the detected ambient temperature.

[0053] Furthermore, in one embodiment of the optical sensor device 1, a variable attenuator 9 is provided, which is arranged between the laser source 2 and the coupler 4. In other embodiments, the variable attenuator 9 chip is integrated and arranged after the coupler 4. The control device 6 is configured to operate the variable attenuator 9 to control the laser power. Additionally, the control device 6 is configured to operate all phase shifters 80.

[0054] In this embodiment of the optical sensor device 1, the detection device 5 is configured to detect the laser light coupled out from the ring resonator 3 via another coupler 41. This is achieved by a third photodiode 5c, which sends a corresponding electrical signal to the control device 6. The control device 6 is designed to control the laser power based on the detected amount of laser light L coupled out from the ring resonator 3. Furthermore, the control device 6 is designed to control the phase shifter 80 based on the detected amount of laser light coupled out from the ring resonator 3.

[0055] In addition, from Figure 4 As can be seen, some components, such as the ring resonator 3, are arranged on the photonic integrated circuit 10. The chip coupler 21, arranged between the laser source 2 and the beam splitter 71, is designed to couple the laser L provided by the laser source 2 to the photonic integrated circuit 10. In other embodiments, the laser source 2 is also heterogeneously or homogeneously integrated on the photonic integrated circuit 10, thus eliminating the need for the chip coupler 21.

[0056] Although the present invention has been fully described above based on preferred embodiments, it is not limited thereto and can be modified in various ways.

[0057] In other embodiments, the ring resonator 3 has a slot waveguide with a slot region located between the first conductor core and the second conductor core, wherein an optical nonlinear material and / or an optical absorbing material is disposed in the slot region. This can improve the nonlinearity of the ring resonator 3 and thereby improve the sensitivity of the optical sensor device 1.

[0058] Although the ring resonator 3 is illustrated as a ring, it is not limited to this shape. In other embodiments, the ring resonator has a "racecourse" or spiral arrangement. Thus, the ring resonator has an extended sensing area, thereby increasing sensitivity due to the larger area.

[0059] In other embodiments, the laser source 2 is manufactured in a chip-integrated manner and integrated with the photonic integrated circuit 10 through homogeneous or heterogeneous integration.

[0060] In other embodiments, the ring resonator 3 and coupler 4 are not implemented using fiber optic assemblies, but rather using a beam splitter and a free-space mirror arrangement. This allows the optical sensor device 1 to be implemented using simple and relatively inexpensive optical components.

Claims

1. An optical sensor device (1), comprising: Laser source (2), used to provide laser (L); An optical ring resonator (3) is arranged to receive a portion of the laser light via a coupler (4), wherein the ring resonator (3) has an optical nonlinear material and / or an optical absorbing material such that the resonance curve (31) of the ring resonator (3) is asymmetric about the resonant wavelength (32) as a function of the wavelength of the laser light (L) to be received, wherein the resonance curve (31) has a side (31a) that rises gently relative to the resonant wavelength and a side (31b) that rises sharply relative to the resonant wavelength (32). A detection device (5) is configured to detect the portion of the laser (L) that is not coupled to the ring resonator (3); The control device (6) is designed to control the laser power of the laser source (2) based on the portion of the detected laser (L) that is not coupled to the ring resonator (3), such that the laser (L) coupled to the ring resonator (3) has a laser wavelength (30) arranged on the steeply rising side (31b) of the resonance curve (31).

2. The optical sensor device (1) according to claim 1, wherein, A beam splitter (71) is provided, which is arranged and constructed to split the laser (L) into a first optical path (11) and a second optical path (12) at a predetermined ratio, wherein the coupler (4) is arranged on the first optical path (11). The detection device (5) is configured to detect laser (L) in the second optical path (12).

3. The optical sensor device (1) according to claim 1, wherein, An optical switch (72) is provided, configured to deflect the laser into a first optical path (11) or a second optical path (12), wherein the coupler (4) is arranged on the first optical path (11). The detection device (5) is configured to detect laser (L) deflected into the second optical path (12), wherein the optical switch (72) is integrated in the coupler (4).

4. The optical sensor device (1) according to any one of the preceding claims, wherein, The wavelength (30) is positioned at the steepest point of the resonance curve (31).

5. The optical sensor device (1) according to any one of the preceding claims, wherein, The ring resonator has a phase shifter (80) configured to shift the phase of the laser (L) coupled to the ring resonator (3).

6. The optical sensor device (1) according to claim 5, wherein, A temperature sensor (82) is provided for detecting ambient temperature, wherein the control device (6) is designed to control the phase shifter (80) based on the detected ambient temperature.

7. The optical sensor device (1) according to any one of the preceding claims, wherein, A variable attenuator (9) is provided, which is in particular chip integrated between the laser source (2) and the coupler (4), wherein the control device (6) is configured to manipulate the variable attenuator (9) to control the laser power.

8. The optical sensor device (1) according to any one of the preceding claims, wherein, The detection device (5) is configured to detect laser light coupled out from the ring resonator (3) via another coupler (41), wherein the control device (6) is designed to control the laser power based on the amount of light detected from the laser light (L) coupled out from the ring resonator (3).

9. The optical sensor device (1) according to claim 8, wherein, The control device (6) is designed to control the phase shifter (80) based on the detected amount of light from the laser coupled out of the ring resonator (3).

10. The optical sensor device (1) according to any one of the preceding claims, wherein, The ring resonator (3) has a slot waveguide with a slot region located between a first conductor core and a second conductor core, wherein the optical nonlinear material and / or optical absorbing material is arranged in the slot region.

11. The optical sensor device (1) according to any one of the preceding claims, wherein, The ring resonator (3) is arranged on the photonic integrated circuit (10), wherein a chip coupler (21) is provided, the chip coupler being designed to couple laser (L) provided by the laser source (2) to the photonic integrated circuit (10).

12. The optical sensor device (1) according to any one of the preceding claims, wherein, The ring resonator (3) and the laser source (2) are heterogeneously or homogeneously integrated on the photonic integrated circuit (10).

13. The optical sensor device (1) according to any one of the preceding claims, wherein, The coupler (4) is constructed as an evanescent wave coupler or a multimode interferometer.

14. The optical sensor device (1) according to any one of the preceding claims, wherein, The ring resonator (3) and the coupler (4) are implemented by the arrangement of a beam splitter and a free-space mirror.

15. The optical sensor device (1) according to any one of the preceding claims, wherein, The ring resonator (3) has a "racecourse" or spiral arrangement.

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