Optical signal sending device

Abstract

The embodiment of the present invention discloses an optical signal sending device, including an optical modulator, a differential driver, and a phase modulator, wherein the optical modulator includes an optical input end, a first modulation area, a connection area, a second modulation area, and an optical output end; the first modulation area includes a first modulation arm and a second modulation arm, the second modulation area includes a third modulation arm and a fourth modulation arm, and each modulation arm includes an optical waveguide and electrodes on both sides thereof. The modulation of the photoelectric signal is realized by driving the two modulation areas with a differential drive signal, and the stacked arrangement of the modulation arms greatly reduces the volume of the optical modulator, thereby facilitating the miniaturization of devices and equipment.

Description

Technical Field

[0001] The present invention relates to the field of optical communications, and in particular to an optical signal sending device. Background Art

[0002] In the field of optical communication technology, the high-speed optical transmitter is the core part of building a high-speed optical network. It is responsible for completing the modulation of the electrical signal to the optical signal of the entire optical network. Therefore, the rate and power consumption of the optical transmitter directly determine the transmission capacity and quality of the entire high-speed optical communication field.

[0003] At present, in short-distance optical interconnection scenarios, silicon photonic modulators are widely used in 100G and below optical modules due to their low cost and small size. However, due to the limitation of free carrier migration rate, the theoretical bandwidth upper limit of silicon photonic modulators is about 70GHz, which makes it unable to meet the device bandwidth requirements of higher optical communications. In long-distance and high-capacity optical communication systems, coherent communication technology is widely used. Currently, the most widely used high-speed device in coherent systems is lithium niobate bulk material devices. Although lithium niobate bulk material modulators can achieve high bandwidth, due to the large size of the bulk material itself, it is difficult to achieve low driving voltage and small size to achieve low cost and low power consumption. Summary of the invention

[0004] The embodiment of the present invention provides an optical signal sending device to realize optoelectronic signal modulation with low cost and low power consumption.

[0005] In a first aspect, an embodiment of the present invention provides an optical signal sending device, including an optical modulator, a differential driver, and a phase modulator, wherein: the optical modulator includes an optical input end, a first modulation area, a connection area, a second modulation area, and an optical output end; the first modulation area includes a first modulation arm and a second modulation arm, the second modulation area includes a third modulation arm and a fourth modulation arm, each modulation arm includes an optical waveguide and electrodes on both sides thereof; the optical input end is used to divide the input continuous light into two paths, and output them to the optical waveguide of the first modulation arm and the optical waveguide of the second modulation arm of the first modulation area respectively; the first modulation arm and the second modulation arm of the first modulation area are used to form an electric field between the electrodes on both sides of their optical waveguides respectively, to modulate the optical signal in the optical waveguide; the connection area is used to connect the first modulation area and the second modulation area, and to divide the optical signal in the first modulation arm and the second modulation arm into two paths; The optical signal is input to the third modulation arm and the fourth modulation arm respectively; the third modulation arm and the fourth modulation arm of the second modulation zone are used to form an electric field between the electrodes on both sides of the optical waveguide respectively to modulate the optical signal in the optical waveguide; the optical output end is used to combine and output the modulated optical signals in the third modulation arm and the fourth modulation arm; the electrodes, including the signal electrode and the ground electrode, are respectively arranged on both sides of the optical waveguide to form an electric field to modulate the light in the optical waveguide, and the signal electrode includes a positive signal electrode and a negative signal electrode; the differential driver includes a positive signal output end and a negative signal output end, which are used to generate a differential drive signal, and the differential drive signal is output to the signal electrode of the first modulation zone and the signal electrode of the second modulation zone respectively; the phase modulator is used to adjust the phase difference between the signal in the first modulation zone and the signal in the second modulation zone. By driving the two modulation zones by the differential drive signal, the modulation of the photoelectric signal is realized, the amplitude voltage of the differential drive is effectively utilized, the modulation efficiency is improved, and the power consumption is reduced.

[0006] In one possible design, the connection area includes two U-shaped connecting waveguides, which are used to connect the waveguides of the first modulation arm and the third modulation arm, and the waveguides connecting the second modulation arm and the fourth modulation arm. The optical waveguides and electrodes in the optical modulator are stacked, and the phase difference generated by the phase modulator is 2π. The stacked arrangement of the modulation arms can greatly reduce the volume of the optical modulator, which is conducive to the miniaturization of devices and equipment.

[0007] In another possible design, the connection area includes two U-shaped connecting waveguides, two straight waveguides, two U-shaped connecting waveguides connected in sequence, a waveguide for connecting the first modulator arm and the third modulator arm, and a waveguide connecting the second modulator arm and the fourth modulator arm. The optical waveguide and the electrode in the optical modulator are stacked, and the phase difference generated by the phase modulator is π. The stacking arrangement of the modulator arms allows the volume of the optical modulator to be greatly reduced, which is conducive to the miniaturization of devices and equipment. It also provides flexibility for the interface on different sides of the device.

[0008] In another possible design, the optical waveguide material is a material having the Pockels effect, and the optical waveguide material includes a lithium niobate film, an organic high molecular polymer, a lithium tantalate film, barium borate, or a gallium arsenide material. Various materials provide manufacturing flexibility.

[0009] In another possible design, the first modulation arm and the second modulation arm share a positive signal electrode, or the third modulation arm and the fourth modulation arm share a negative signal electrode, thereby reducing the size of the device.

[0010] In another possible design, the phase modulator is an electrical delay line, and the differential driver outputs the differential drive signal to the positive signal electrode or the negative signal electrode through at least one electrical delay line. The electrical delay line is an adjustable electrical delay line. The delay line provides modulation flexibility.

[0011] In another possible design, the phase modulator is a heater located in the connection area. The heater material includes nickel titanium or metal. Phase modulation by the heater improves the flexibility of the device.

[0012] In a second aspect, an embodiment of the present invention provides an optical module, comprising the above-mentioned optical signal sending device and optical signal receiving device, wherein the optical signal receiving device is used to receive an optical signal.

[0013] In a third aspect, an embodiment of the present invention provides an optical communication device, including a laser and an optical signal sending device, wherein the laser is used to output continuous light.

[0014] The above-mentioned solution provided by the embodiment of the present invention realizes the modulation of the photoelectric signal by driving two modulation areas with a differential driving signal, which greatly reduces the driving voltage, improves the modulation efficiency, and reduces the power consumption of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of an optical communication system provided by an embodiment of the present invention;

[0016] Figure 2 A schematic diagram of the structure of an optical signal sending device provided in an embodiment of the present invention;

[0017] Figure 3 A schematic diagram of the structure of another optical signal sending device provided in an embodiment of the present invention;

[0018] Figure 4 A schematic diagram of the structure of another optical signal sending device provided in an embodiment of the present invention;

[0019] Figure 5 A schematic diagram of the structure of another optical signal sending device provided in an embodiment of the present invention;

[0020] Figure 6A schematic diagram of the structure of another optical signal sending device provided in an embodiment of the present invention;

[0021] Figure 7 A schematic diagram of the structure of another optical signal sending device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0023] like Figure 1 As shown, an embodiment of the present invention provides an optical signal sending device 102. In an optical transmission system, a sending end includes a light source 101 and an optical signal sending device 102. The optical signal sending device 102 includes an optical modulator 111, a differential driver 112, and a phase modulator 113. The differential driver 112 is used to output a differential drive signal to the optical modulator 111 according to an electrical signal to be transmitted. The optical modulator 111 is used to modulate the continuous light output by the light source 101 into a signal light according to the differential drive signal, and the phase modulator 113 is used to adjust the phase difference between the signals. In this way, the electrical signal to be transmitted is modulated into an optical signal, and the modulated optical signal is transmitted to the receiving end through the optical fiber, and is received and processed by the optical signal receiving device 103.

[0024] The light source 101 and the optical signal sending device 102 may be located in the same physical device, such as an optical communication device. The laser outputs continuous light, and the optical signal sending device modulates the continuous light into signal light and outputs it to the receiving side.

[0025] In addition, in the optical communication device, the optical module of the interface includes the above-mentioned optical signal sending device and optical signal receiving device to realize the bidirectional sending and receiving function.

[0026] like Figure 2 , which is a schematic diagram of the structure of an optical signal sending device provided by an embodiment of the present invention. The optical signal sending device includes an optical modulator 201, a differential driver 202, and a phase modulator 203, wherein the optical modulator 201 includes: an optical input end 211, a first modulation area including a first modulation arm 212 and a second modulation arm 213, a connection area 214, a second modulation area including a third modulation arm 215 and a fourth modulation arm 216, and an optical output end 217; each modulation arm includes an optical waveguide and electrodes on both sides thereof;

[0027] An optical input end 211 is used to split the input continuous light into two paths, and output them to the optical waveguide of the first modulation arm and the optical waveguide of the second modulation arm of the first modulation area respectively;

[0028] The first modulation arm 212 and the second modulation arm 213 of the first modulation zone are used to form an electric field between electrodes on both sides of the optical waveguide to modulate the optical signal in the optical waveguide;

[0029] A connection area 214, used to connect the first modulation area and the second modulation area, and input the optical signals in the first modulation arm and the second modulation arm to the third modulation arm and the fourth modulation arm respectively; Figure 2 The connecting area in the embodiment is two U-shaped waveguides, which respectively connect the two modulation arms of the first modulation area and the second modulation area.

[0030] The third modulation arm 215 and the fourth modulation arm 216 of the second modulation zone are used to form an electric field between electrodes on both sides of the optical waveguide to modulate the optical signal in the optical waveguide;

[0031] The optical output end 217 is used to combine and output the modulated optical signals in the third modulation arm and the fourth modulation arm;

[0032] The electrodes on both sides of the optical waveguide in each modulation arm include a signal electrode P and a ground electrode G, which are respectively arranged on both sides of the optical waveguide and are used to form an electric field to modulate the continuous light in the optical waveguide. The signal electrodes include a positive signal electrode "P+" and a negative signal electrode "P-";

[0033] A differential driver 202, for generating a differential drive signal, including a positive signal output terminal "RF+" and a negative signal output terminal "RF-", the differential drive signal is output to the positive signal electrode of the first modulation area and the negative signal electrode of the second modulation area respectively;

[0034] The phase modulator 203 is used to adjust the phase difference between the optical signal in the first modulation area and the optical signal in the second modulation area. Figure 2 The phase modulator in the embodiment is an electrical delay line, and two electrical delay lines connect the differential drive signal output by the differential drive signal to the positive signal electrode and the negative signal electrode of the two modulation areas. The phase difference between the two delay lines is 2π, so that the RF+ and RF- signals still retain the original π phase. Furthermore, at least one of the two delay lines is adjustable, and the adjustable delay line can be adjusted within the range of 0 to 2π, so as to flexibly adjust the phase difference between the two signals.

[0035] Figure 2 In the embodiment, the optical input end and the optical output end are located on the same side of the device. The optical waveguides and electrodes of the four modulation arms are arranged in a stacked manner. The optical waveguide material is a material having a Pockels Effect, including lithium niobate thin film material, organic high molecular polymer material, lithium tantalate thin film material, barium borate, gallium arsenide and other materials having a Pockels Effect.

[0036] Figure 2In the embodiment shown, modulation of the photoelectric signal is achieved by driving two modulation areas with a differential drive signal. The stacked arrangement of the modulation arms greatly reduces the volume of the optical modulator, which is beneficial to the miniaturization of devices and equipment. This differential method effectively utilizes the amplitude voltage of the differential drive, improves the modulation efficiency, and reduces power consumption.

[0037] In some usage scenarios, the input light and output light of the optical modulator need to be distributed on both sides of the device. Figure 3 In the illustrated embodiment, the input light and the output light are on the left and right sides of the device respectively. The optical signal sending device includes an optical modulator 301, a differential driver 302, and a phase modulator 303. The optical modulator 301 includes: an optical input end 311, a first modulation area including a first modulation arm 312 and a second modulation arm 313, a connection area 314, a second modulation area including a third modulation arm 315 and a fourth modulation arm 316, and an optical output end 317.

[0038] Figure 3 In the figure, the connection area 314 includes two U-shaped waveguides and a pair of straight waveguides in the middle, which are used to connect the two modulation areas. The phase modulator 303 is two electrical delay lines connected to the output of the differential driver, with a phase difference of π. The functions of other parts are similar to Figure 2 The corresponding parts in have the same functions and will not be described in detail.

[0039] Figure 3 In the embodiment, the optical input end and the optical output end are located on different sides of the device. The optical waveguides and electrodes of the four modulation arms, as well as part of the waveguides of the connection area 314, are arranged in a stacked manner. Similarly, the optical waveguide material can be a linear photoelectric effect material, including lithium niobate film material, organic high molecular polymer material, or lithium tantalate film material. Such an implementation method improves the flexibility of the device and greatly reduces the volume of the optical modulator, which is conducive to the miniaturization of devices and equipment.

[0040] The phase modulator 113 can also be a heater, such as Figure 4 and Figure 5 As shown, the phase modulator 418 or 518 does not use an electric delay line, but uses a heater, which is located in the connection area 414 or 514 and connected to the two waveguides in the connection area. The adjustment range of the heater is at least within the range of 2π. Different phase modulators increase the flexibility of the device. Figure 4 The other components in Figure 2 Parts with the same position / function are the same. Figure 5 The other components in Figure 3 The same parts in the same position / function are the same. For example, Figure 4The optical signal sending device in the embodiment includes an optical modulator 401, a differential driver 402, and a phase modulator 403, wherein the optical modulator 401, the differential driver 402, and the phase modulator 403 are respectively Figure 2 The optical modulator 201, the differential driver 202, and the phase modulator 203 are the same as those in FIG. Figure 2 The relevant description will not be repeated here.

[0041] like Figure 6 , which is a schematic diagram of the structure of another optical signal transmitting device provided by an embodiment of the present invention, that is, an adjustable delay is set inside the differential driver. The differential driver 602 is used to generate a differential drive signal and has the function of adjusting the phase difference between the signal in the first modulation area and the signal in the second modulation area as a phase modulator. The two signal input ports of the modulator can be connected by cables or metal electrodes. The functions of other parts are similar to Figure 2 The corresponding parts in have the same functions and will not be described in detail.

[0042] Figure 6 In the embodiment shown, the phase difference between the two signals at the positive signal output terminal "RF+" and the negative signal output terminal "RF-" is adjusted by the phase adjustment function of the differential driver 602, while retaining the original π phase, so that the electric drive signal is completely loaded onto the modulator, and the drive amplitude is maximized, thereby increasing the signal amplitude.

[0043] like Figure 7 , which is a schematic diagram of the structure of another optical signal transmitting device provided by an embodiment of the present invention, that is, an adjustable delay is set inside the differential driver. The differential driver 702 is used to generate a differential drive signal and has a phase modulator to adjust the phase difference between the signal in the first modulation area and the signal in the second modulation area. The two signal input ports of the modulator can be connected by a cable or a metal electrode. The functions of other parts are similar to Figure 3 The corresponding parts in have the same functions and will not be described in detail.

[0044] Figure 7 In the embodiment shown, the phase difference between the two signals at the positive signal output terminal "RF+" and the negative signal output terminal "RF-" is adjusted to a 2π phase through the phase adjustment function of the differential driver 702, so that the electric drive signal is completely loaded onto the modulator and the drive amplitude is maximized, thereby increasing the signal amplitude.

[0045] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art may understand and implement other variations of the disclosed embodiments by reviewing the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality of components or steps.

[0046] Although the present invention has been described in conjunction with specific features and embodiments thereof, it is apparent that various modifications and combinations thereof may be made. Accordingly, this specification and the drawings are merely exemplary illustrations of the present invention as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of the present invention. Obviously, a person skilled in the art may make various modifications and variations to the present invention without departing from the scope of the present invention. Thus, the present invention is intended to include such modifications and variations as fall within the scope of the claims of the present invention and their equivalents.

Claims

1. An optical signal sending device, characterized in that: The invention comprises an optical modulator, a differential driver, and a phase modulator, wherein: The optical modulator comprises an optical input end, a first modulation area, a connection area, a second modulation area, and an optical output end; the first modulation area comprises a first modulation arm and a second modulation arm, the second modulation area comprises a third modulation arm and a fourth modulation arm, and each modulation arm comprises an optical waveguide and electrodes on both sides thereof; The optical input end is used to split the input continuous light into two paths, and output them to the optical waveguide of the first modulation arm and the optical waveguide of the second modulation arm of the first modulation area respectively; The first modulation arm and the second modulation arm of the first modulation zone are used to form an electric field between electrodes on both sides of the optical waveguide to modulate the optical signal in the optical waveguide; The connection area is used to connect the first modulation area and the second modulation area, and input the optical signals in the first modulation arm and the second modulation arm to the third modulation arm and the fourth modulation arm respectively; the connection area includes two connecting waveguides, a waveguide for connecting the first modulation arm and the third modulation arm, and a waveguide for connecting the second modulation arm and the fourth modulation arm; The third modulation arm and the fourth modulation arm of the second modulation zone are used to form an electric field between electrodes on both sides of the optical waveguide to modulate the optical signal in the optical waveguide; The optical output end is used to combine and output the modulated optical signals in the third modulation arm and the fourth modulation arm; The electrodes include a signal electrode and a ground electrode, which are respectively arranged on both sides of the optical waveguide and are used to form an electric field to modulate the light in the optical waveguide. The signal electrodes include a positive signal electrode and a negative signal electrode. The optical waveguide of the first modulation arm, the optical waveguide of the second modulation arm, the optical waveguide of the third modulation arm, and the optical waveguide of the fourth modulation arm and the electrodes are arranged in a stacked manner. The first modulation arm and the second modulation arm share one positive signal electrode, and the third modulation arm and the fourth modulation arm share one negative signal electrode. The differential driver comprises a positive signal output terminal and a negative signal output terminal, and is used to generate a differential drive signal, and the differential drive signal is output to the signal electrode of the first modulation area and the signal electrode of the second modulation area respectively; The phase modulator is used to adjust the phase difference between the signal in the first modulation area and the signal in the second modulation area.

2. The optical signal transmitting device according to claim 1, characterized in that: The connection area includes two U-shaped connecting waveguides, a waveguide for connecting the first modulation arm and the third modulation arm, and a waveguide for connecting the second modulation arm and the fourth modulation arm.

3. The optical signal transmitting device according to claim 2, characterized in that: The optical waveguide and the electrode in the optical modulator are stacked and arranged, and the phase difference generated by the phase modulator is 2π.

4. The optical signal transmitting device according to claim 1, wherein: The connection area includes two U-shaped connection waveguides, two straight waveguides, and two U-shaped connection waveguides connected in sequence. The connection area is used to connect the waveguides of the first modulation arm and the third modulation arm, and the waveguides of the second modulation arm and the fourth modulation arm.

5. The optical signal transmitting device according to claim 4, characterized in that: The optical waveguide and the electrode in the optical modulator are stacked and arranged, and the phase difference generated by the phase modulator is π.

6. The optical signal sending device according to any one of claims 1 to 5, characterized in that: The optical waveguide material is a material having the Pockels effect.

7. The optical signal sending device according to any one of claims 1 to 5, characterized in that: The optical waveguide material includes lithium niobate film, organic high polymer, lithium tantalate film, barium borate, or gallium arsenide material.

8. The optical signal sending device according to any one of claims 1 to 5, characterized in that: The phase modulator is an electrical delay line, and the differential driver outputs a differential drive signal to the positive signal electrode or the negative signal electrode through at least one electrical delay line.

9. The optical signal transmitting device according to claim 8, characterized in that: The electric delay line is an adjustable electric delay line.

10. The optical signal sending device according to any one of claims 1 to 5, characterized in that: The phase modulator is a heater, which is located in the connection area.

11. The optical signal transmitting device according to claim 10, characterized in that: The material of the heater includes metal.

12. An optical module, characterized in that: It comprises an optical signal sending device and an optical signal receiving device as described in any one of claims 1 to 11, wherein the optical signal receiving device is used to receive an optical signal.

13. An optical communication device, characterized in that: An optical signal sending device comprising a laser as claimed in any one of claims 1 to 11, wherein the laser is used to output the continuous light.

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