Optical integrated circuit element

Abstract

To provide an optical integrated circuit element capable of avoiding an increase in size.SOLUTION: An optical integrated circuit element includes: a first optical circuit element and a second optical circuit element each requiring temperature control; and a temperature sensor that measures temperatures of the first optical circuit element and the second optical circuit element.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to integrated optical devices. [Background technology]

[0002] BACKGROUND ART Multi-wavelength laser sources (MWLS) are known, which are light sources that output laser light of a plurality of mutually different wavelengths (for example, Patent Document 1).

[0003] The MWLS of Patent Document 1 has two laser drivers and two wavelength lockers corresponding to the two laser drivers, respectively, for locking the optical wavelengths of the two laser drivers to target wavelengths. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] US Patent Application Publication No. 2005 / 0063429 Summary of the Invention [Problem to be solved by the invention]

[0005] A wavelength locker has a monitor unit that monitors the wavelength (frequency) of light output from a laser driver. The monitor unit may include a ring resonator or the like as an optical filter. The characteristics of a ring resonator or the like are likely to change depending on temperature. Therefore, in order to accurately measure the wavelength, it is necessary to control the temperature of the monitor unit to a target temperature corresponding to the target wavelength.

[0006] The present inventors have found that providing a plurality of temperature sensors corresponding to a plurality of wavelength lockers in an optical integrated circuit element results in an increase in the size of the optical integrated circuit element. This problem is particularly pronounced in the case of an optical integrated circuit element. Furthermore, this problem is not limited to wavelength lockers, but applies to all optical circuit elements that require temperature control.

[0007] An object of the present disclosure is to provide an optical integrated circuit element that can avoid an increase in size. It should be noted that this object is only one of multiple objects that the multiple embodiments disclosed in this specification aim to achieve. Other objects or problems and novel features will become apparent from the description of this specification or the accompanying drawings. [Means for solving the problem]

[0008] An optical integrated circuit device according to the present disclosure includes a first optical circuit element and a second optical circuit element each requiring temperature control, and a temperature sensor for measuring the temperatures of the first optical circuit element and the second optical circuit element. [Effects of the Invention]

[0009] The present disclosure makes it possible to provide an optical integrated circuit element that can avoid an increase in size. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an example of an optical integrated circuit element according to the present disclosure. [Figure 2] 1A and 1B are diagrams illustrating the arrangement of an optical circuit element and a temperature sensor in an optical integrated circuit element according to the present disclosure. [Figure 3] 10 is another diagram illustrating the arrangement of the optical circuit element and the temperature sensor in the optical integrated circuit element of the present disclosure. FIG. [Figure 4] 1 illustrates an example of a light output device of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described with reference to the drawings. In this disclosure, the drawings may relate to one or more embodiments. Furthermore, each element in the drawings may apply to one or more embodiments. Furthermore, in the embodiments, identical or equivalent elements are given the same reference numerals, and redundant explanations will be omitted.

[0012] First Embodiment Fig. 1 is a diagram showing an example of an optical integrated circuit device according to the present disclosure. In Fig. 1, an optical integrated circuit device 10 includes optical circuit elements 11-1 and 11-2 and a temperature sensor 12. In the following description, when there is no need to distinguish between the optical circuit elements 11-1 and 11-2, each of the optical circuit elements 11-1 and 11-2 may be referred to simply as the optical circuit element 11, or the optical circuit elements 11-1 and 11-2 may be collectively referred to as the optical circuit element 11.

[0013] The optical circuit element 11 is an element that requires temperature control. For example, as described above, the optical circuit element 11 may include a ring resonator (not shown) as an optical filter and may be a circuit element (monitor unit) for monitoring the wavelength (frequency) of light.

[0014] The temperature sensor 12 measures the temperatures of the optical circuit elements 11-1 and 11-2.

[0015] As described above, in the first embodiment, the optical integrated circuit device 10 includes the optical circuit elements 11-1 and 11-2, and the temperature sensor 12 that measures the temperatures of the optical circuit elements 11-1 and 11-2.

[0016] This configuration of the optical integrated circuit element 10 allows the size of the optical integrated circuit element to be made smaller than when a temperature sensor is provided for each optical circuit element.

[0017] For simplicity of explanation, the above description has been given assuming that there are two optical circuit elements 11 and one temperature sensor 12, but the present disclosure is not limited to this. For example, in the case of three optical circuit elements 11-1, 11-2, and 11-3, the optical integrated circuit element 10 may have one temperature sensor 12 that measures the temperatures of the optical circuit elements 11-1 and 11-2, and another temperature sensor 12 that measures the temperatures of the optical circuit elements 11-2 and 11-3. In short, it is sufficient that the optical integrated circuit element 10 has fewer temperature sensors 12 than the number of optical circuit elements 11, as long as the temperatures of the optical circuit elements 11 can be measured by the temperature sensors 12.

[0018] Second Embodiment The second embodiment relates to the arrangement of the optical circuit element and the temperature sensor.

[0019] Fig. 2 is a diagram illustrating the arrangement of optical circuit elements and temperature sensors in an optical integrated circuit device according to the present disclosure, and Fig. 3 is another diagram illustrating the arrangement of optical circuit elements and temperature sensors in an optical integrated circuit device according to the present disclosure.

[0020] As shown in Fig. 2, the optical integrated circuit device 10 includes a plate-shaped substrate 13. Optical circuit devices 11-1 and 11-2 are disposed in mounting areas AR1 and AR2, respectively, on the substrate 13 shown in Fig. 2. Furthermore, the temperature sensor 12 is disposed in mounting area AR3 on the substrate 13 shown in Fig. 2.

[0021] The arrangement areas AR1 and AR2 are located symmetrically with respect to a plane of symmetry PL1 that is perpendicular to the surface of the substrate 13. The arrangement area AR3 is included in an area AR4 that is sandwiched between the arrangement areas AR1 and AR2. This allows the optical circuit elements 11-1 and 11-2 and the temperature sensor 12 to be arranged efficiently.

[0022] For example, the arrangement area AR1 and the arrangement area AR2 have mutually congruent rectangular shapes. The arrangement area AR3 also has a rectangular shape. The arrangement area AR3 may or may not be congruent with the arrangement area AR1 and the arrangement area AR2. Also, for example, the center of gravity of the arrangement area AR1, the center of gravity of the arrangement area AR2, and the arrangement area AR3 may be located on the straight line LN1. This allows the temperature sensor 12 to accurately measure the temperature of the central portion of the optical circuit element 11 (i.e., the portion corresponding to the straight line LN1), which is expected to be the hottest part of the optical circuit element 11.

[0023] The separation distance d1 between the arrangement areas AR1 and AR2 is, for example, at least the length required to place the temperature sensor 12 and at least a distance (for example, 300 μm) at which it is assumed that no thermal interference occurs between the optical circuit elements 11-1 and 11-2. The separation distance d2 between the arrangement areas AR1 and AR3 and the separation distance d3 between the arrangement areas AR2 and AR3 are, for example, 0 μm to 300 μm, respectively.

[0024] As described above, according to the second embodiment, in the optical integrated circuit device 10, the optical circuit elements 11-1 and 11-2 are disposed in the arrangement areas AR1 and AR2, respectively, which are symmetrical with respect to the plane of symmetry PL1 orthogonal to the substrate 13 and are spaced a predetermined distance apart on the substrate 13. The temperature sensor 12 is disposed in the arrangement area AR3, which is included in the area AR4 sandwiched between the arrangement areas AR1 and AR on the substrate 13.

[0025] This configuration of the optical integrated circuit device 10 allows the optical circuit elements 11-1 and 11-2 and the temperature sensor 12 to be efficiently arranged on the substrate 13, thereby enabling further miniaturization of the device.

[0026] Third Embodiment The third embodiment relates to a light output device.

[0027] 4 is a diagram showing an example of a light output device according to the present disclosure. In FIG. 4, light output device 20 includes light output elements 21-1 and 21-2, control units 22-1 and 22-2, temperature control unit 23, TEC (Thermo-Electric Cooler) element 24, and optical integrated circuit element 10.

[0028] Light output element 21-1 outputs light of a first wavelength (hereinafter sometimes referred to as "first light"). Light output element 21-2 outputs light of a second wavelength (hereinafter sometimes referred to as "second light"). In other words, light output device 20 is a two-wavelength tunable light source. The first wavelength and the second wavelength may be the same or different. Note that although wavelengths are used in the description here, frequencies may be used instead of wavelengths.

[0029] The first light is split by the optical splitter, and a portion of the first light is input to the optical circuit element 11-1 of the optical integrated circuit device 10. The second light is split by the optical splitter, and a portion of the second light is input to the optical circuit element 11-2 of the optical integrated circuit device 10.

[0030] The optical circuit element 11 includes a waveguide 11B, an optical filter 11C, and photodiodes (PD) 11D and 11E. A first light input to the optical circuit element 11-1 is split by the optical splitter of the optical circuit element 11. A portion of the first light split by the optical splitter passes through the waveguide 11B, which transmits light as is, and is input to the PD 11D. The PD 11D outputs an electrical signal corresponding to the intensity of the light received through the waveguide 11B to the control unit 22-1. The other portion of the first light split by the optical splitter passes through the optical filter 11C, which transmits light with a transmittance corresponding to the wavelength, and is input to the PD 11E. The optical filter 11C includes a ring resonator. The PD 11E outputs an electrical signal corresponding to the intensity of the light received through the optical filter 11C to the control unit 22-1. The ratio of the current value of the electrical signal received from PD 11D to the current value of the electrical signal received from PD 11E corresponds to the monitor value for the wavelength of the first light.

[0031] The control unit 22-1 controls the optical circuit element 11-1 based on the monitor value for the wavelength of the first light and the target wavelength of the first light so that the wavelength of the light output from the optical circuit element 11-1 approaches the target wavelength.

[0032] The optical circuit element 11-2 has the same basic configuration as the optical circuit element 11-1. The optical circuit element 11-2 and the control unit 22-2 behave in the same manner as the optical circuit element 11-1 and the control unit 22-1 with respect to the second light.

[0033] The temperature control unit 23 controls the TEC element 24 based on the measured temperature received from the temperature sensor 12 and the target temperature, thereby controlling the measured temperature to approach the target temperature. The target temperature is a temperature corresponding to the target wavelength of the first light and the target wavelength of the second light. The optical circuit elements 11-1 and 11-2 and the temperature sensor 12 are disposed on the TEC element 24. Therefore, by controlling the measured temperature of the temperature sensor 12 to approach the target temperature, the temperatures of the optical circuit elements 11-1 and 11-2 can be brought closer to the target temperature. The TEC element 24 is, for example, a Peltier element.

[0034] Each drawing is merely an example for describing one or more embodiments. Each drawing may relate not only to one particular embodiment, but also to one or more other embodiments. As will be understood by those skilled in the art, various features or steps described with reference to any one drawing can be combined with features or steps shown in one or more other drawings to create, for example, an embodiment not explicitly shown or described. Not all features or steps shown in any one drawing are necessary to describe an exemplary embodiment, and some features or steps may be omitted. The order of steps described in any drawing may be changed as appropriate.

[0035] A part or all of the above-described embodiments can be described as, but not limited to, the following supplementary notes. (Appendix 1) a first optical circuit element and a second optical circuit element each requiring temperature control; a temperature sensor for measuring the temperatures of the first optical circuit element and the second optical circuit element; An optical integrated circuit device comprising: (Appendix 2) the first optical circuit element and the second optical circuit element are disposed in a first arrangement area and a second arrangement area, respectively, which are symmetrical with respect to a plane of symmetry perpendicular to the substrate and spaced a predetermined distance apart from each other on the substrate; the temperature sensor is disposed in a third disposition area included in an area sandwiched between the first disposition area and the second disposition area on the substrate; 10. An optical integrated circuit device according to claim 1. (Appendix 3) each of the first optical circuit element and the second optical circuit element includes a ring resonator type wavelength filter; 3. An optical integrated circuit device according to claim 1 or 2. (Appendix 4) the first optical circuit element is a monitor unit that monitors the wavelength of light output by the first optical output element, the second optical circuit element is a monitor unit that monitors the wavelength of the light output by the second optical output element; 4. An optical integrated circuit device according to claim 3. (Appendix 5) the predetermined distance is a distance at which it can be assumed that no thermal interference occurs between the first optical circuit element and the second optical circuit element; The distance between the first optical circuit element and the temperature sensor and the distance between the first optical circuit element and the temperature sensor are each 0 μm to 300 μm. 3. An optical integrated circuit device according to claim 2. (Appendix 6) The predetermined distance is 300 μm or more. 6. An optical integrated circuit device according to claim 5. [Explanation of symbols]

[0036] 10 Optical integrated circuit element 11 Optical circuit elements 11B Waveguide 11C Optical Filter 11D Photodiode (PD) 11E Photodiode (PD) 12 Temperature Sensor 13 PCB 20 Optical output device 21 Optical output element 22 Control Unit 23 Temperature control unit 24 TEC element

Claims

1. a first optical circuit element and a second optical circuit element each requiring temperature control; a temperature sensor for measuring the temperatures of the first optical circuit element and the second optical circuit element; An optical integrated circuit device comprising:

2. the first optical circuit element and the second optical circuit element are disposed in a first arrangement area and a second arrangement area, respectively, which are symmetrical with respect to a plane of symmetry perpendicular to the substrate and are spaced a predetermined distance apart from each other on the substrate; the temperature sensor is disposed in a third disposition area included in an area sandwiched between the first disposition area and the second disposition area on the substrate; 2. The optical integrated circuit device according to claim 1.

3. each of the first optical circuit element and the second optical circuit element includes a ring resonator type wavelength filter; 3. The optical integrated circuit device according to claim 1.

4. the first optical circuit element is a monitor unit that monitors the wavelength of light output by the first optical output element, the second optical circuit element is a monitor unit that monitors the wavelength of the light output by the second optical output element; 4. The optical integrated circuit device according to claim 3.

5. the predetermined distance is a distance at which it can be assumed that no thermal interference occurs between the first optical circuit element and the second optical circuit element; a separation distance between the first optical circuit element and the temperature sensor, and a separation distance between the first optical circuit element and the temperature sensor are each 0 μm to 300 μm; 3. The optical integrated circuit device according to claim 2.

6. The predetermined distance is 300 μm or more.

6. The optical integrated circuit device according to claim 5.

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