A laser with improved electro-optical efficiency

Abstract

The application discloses a laser with improved electro-optical efficiency, comprising an active device, a tapered waveguide, a bottom waveguide and a substrate; the bottom waveguide is arranged on the substrate; the active device is arranged in parallel with the tapered waveguide on the same layer and is arranged in vertical stacking with the bottom waveguide; the active device and the tapered waveguide have the same waveguide structure, and the active device is further provided with an active device top electrode and an active device bottom electrode, and the tapered waveguide is further provided with a tapered waveguide top electrode and a tapered waveguide bottom electrode. The application improves the tapered waveguide coupling structure, so that the current injected by the active device with the tapered waveguide can be distributed as required, that is, the ratio of the current injected into the tapered waveguide part to the total injected current is controllable, and in addition, the application can adjust the current consumed by the tapered waveguide according to different application and device design requirements, so that the influence of the tapered waveguide on the device performance can be reduced to the minimum.

Description

Technical Field

[0001] This invention relates to the field of laser technology, and more particularly to a laser with improved electro-optical efficiency. Background Technology

[0002] Photonic integrated circuits (PICs) provide an integration technology platform that is increasingly being used to form complex optical circuits. PIC technology allows multiple optical devices (both active and passive) to be integrated onto a single substrate. For example, a PIC can include integrated lasers, integrated receivers, waveguides, detectors, semiconductor optical amplifiers (SOAs), gratings, and other active or passive semiconductor optical devices.

[0003] Vertical integration of two waveguide devices in multiple optical devices is a widely used integration method, employed for monolithic integration based on InP and heterogeneous integration of InP and silicon. In photonic integrated circuits, the transformation of light transmission paths from one waveguide to another, as well as the conversion of optical modes, are achieved through tapered waveguides. When the tapered waveguide is an active waveguide structure, such as a laser or amplifier waveguide structure, it can cause significant absorption loss in the converted light waves.

[0004] To address the aforementioned technical issues and reduce the loss of the tapered waveguide, it is necessary to inject current into the tapered waveguide. Since this injected current is part of the laser drive current or amplifier pump current, this method of reducing loss comes at the cost of reducing the efficiency of the laser or amplifier. Therefore, it is necessary to improve it. Summary of the Invention

[0005] The purpose of this invention is to provide a laser with improved electro-optic efficiency, which is beneficial to improving device efficiency and reducing power consumption.

[0006] To achieve the above objectives, the following technical solution is adopted:

[0007] A laser with improved electro-optic efficiency includes an active device, a tapered waveguide, a bottom waveguide, and a substrate; the bottom waveguide is disposed on the substrate; the active device and the tapered waveguide are disposed parallel to each other on the same layer and stacked perpendicularly to each other with the bottom waveguide; the active device and the tapered waveguide have the same waveguide structure, and the active device is further provided with a top electrode and a bottom electrode, and the tapered waveguide is further provided with a top electrode and a bottom electrode; the active device is used to achieve photoelectric properties by applying a voltage or injecting current between the top electrode and the bottom electrode, and to transmit light propagating in the waveguide to the bottom waveguide through the tapered waveguide.

[0008] Furthermore, it also includes a top doped layer and a bottom doped layer; the top doped layer is disposed below the top electrode of the active device and the top electrode of the tapered waveguide, and forms an electrical contact with them; the bottom doped layer is disposed above the bottom waveguide, and is located below the bottom electrode of the active device and the bottom electrode of the tapered waveguide, and forms an electrical contact with them.

[0009] Furthermore, an active material layer is provided between the bottom doped layer and the top doped layer.

[0010] Furthermore, the tapered waveguide and the active device are connected in parallel in the circuit.

[0011] Furthermore, it also includes electronic blocking structures to increase the impedance of the tapered waveguide.

[0012] Furthermore, the number of the electronic blocking structures is at least one, which may be located between the top electrode of the active device and the top electrode of the tapered waveguide, or between the bottom electrode of the active device and the bottom electrode of the tapered waveguide, or between the top electrode of the tapered waveguide and its bottom electrode.

[0013] Furthermore, the electron blocking structure can utilize the intrinsic resistance of the top doped layer and the bottom doped layer, or employ resistance formed by etching or ion implantation of the top doped layer and the bottom doped layer in different shapes.

[0014] Furthermore, the top doped layer and the bottom doped layer can be p / n doped or n / p doped; the bottom electrode of the active device and the bottom electrode of the tapered waveguide are an integral structure.

[0015] Furthermore, the active device can be any of the following: laser, amplifier, modulator, detector, attenuator, or isolator.

[0016] Furthermore, the bottom waveguide can be any of the following devices: passive optical waveguide, modulator, or isolator.

[0017] By adopting the above solution, the beneficial effects of the present invention are:

[0018] Compared to conventional lasers, this invention improves the tapered waveguide coupling structure, enabling the current injected into active devices with tapered waveguides to be distributed on demand. That is, the ratio of the current injected into the tapered waveguide portion to the total injected current is controllable. In addition, this invention can adjust the current consumed by the tapered waveguide according to different applications and device design requirements, so that its impact on device performance can be minimized. Attached Figure Description

[0019] Figure 1 This is a top view of the present invention;

[0020] Figure 2 This is a longitudinal cross-sectional view of the present invention;

[0021] The following are explanations of the labels in the attached diagram:

[0022] 1—Active device; 2—Tapered waveguide;

[0023] 3—Top electrode of active device; 4—First electron blocking structure;

[0024] 5—Bottom electrode of active device; 6—Top electrode of tapered waveguide;

[0025] 7—Top doped layer; 8—Active material layer;

[0026] 9—Bottom doped layer; 10—Bottom waveguide;

[0027] 11—Substrate; 12—Second electron-blocking structure;

[0028] 13—Bottom electrode of tapered waveguide. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0030] Reference Figures 1 to 2 As shown, the present invention provides a laser with improved electro-optic efficiency, including an active device 1, a tapered waveguide 2, a bottom waveguide 10, and a substrate 11; the bottom waveguide 10 is disposed on the substrate 11; the active device 1 and the tapered waveguide 2 are disposed in parallel and spaced apart on the same layer, and are stacked perpendicularly to each other with the bottom waveguide 10; the active device 1 and the tapered waveguide 2 have the same waveguide structure, and the active device 1 is further provided with an active device top electrode 3 and an active device bottom electrode 5, and the tapered waveguide 2 is further provided with a tapered waveguide top electrode 6 and a tapered waveguide bottom electrode 13; the active device 1 is used to achieve photoelectric performance by applying voltage or injecting current between the active device top electrode 3 and the bottom electrode, and transmits light propagating in the waveguide to the bottom waveguide 10 through the tapered waveguide 2.

[0031] Continue to refer to Figures 1 to 2As shown, in one embodiment, the active device 1 and the tapered waveguide 2 are arranged in parallel at intervals on the same layer. The active device 1, the tapered waveguide 2, and the bottom waveguide 10 are integrated in a vertically stacked manner, and mode conversion is achieved through the tapered waveguide 2. In this embodiment, a top doping layer 7 and a bottom doping layer 9 are also included. The top doping layer 7 is arranged below the top electrode 3 of the active device and the top electrode 6 of the tapered waveguide, and forms an electrical contact with them. The bottom doping layer 9 is arranged above the bottom waveguide 10 and is located below the bottom electrode 5 of the active device and the bottom electrode 13 of the tapered waveguide, and forms an electrical contact with them. The top doping layer 7 and the bottom doping layer 9 can be p / n doped or n / p doped. The specific doping type can be designed by those skilled in the art according to actual needs. In addition, an active material layer 8 is provided between the bottom doping layer 9 and the top doping layer 7.

[0032] In one embodiment, the tapered waveguide 2 and the active device 1 are connected in parallel in the circuit. The ratio of the resistance values ​​of the tapered waveguide 2 and the active device 1 determines the ratio of the current consumed in the active device 1 and the tapered waveguide 2, which is inversely proportional to the electro-optical efficiency of the laser. In this embodiment, the active device 1 and the tapered waveguide 2 each have a top electrode 3 and a top electrode 6, respectively. Their bottom electrodes are shared by the active device 1 and the tapered waveguide 2, that is, the bottom electrode 5 of the active device and the bottom electrode 13 of the tapered waveguide are an integral structure. The active device 1 and the tapered waveguide 2 each have resistance values ​​R1 and R2, which are connected in parallel. By adjusting the ratio between R1 and R2, that is, adjusting the value of R1 / R2, the current consumed by the tapered waveguide 2 can be adjusted, so that its impact on the performance of the active device 1 is minimized. The ratio between R1 and R2 can be freely adjusted by those skilled in the art according to the design requirements of different devices.

[0033] In one embodiment, an electronic blocking structure is also included to increase the impedance of the tapered waveguide 2, reduce the ratio of the resistance of the tapered waveguide 2 to that of the active device 1, and improve the electro-optical efficiency of the laser. The number of the electronic blocking structure is at least one, which may be located between the top electrode 3 of the active device and the top electrode 6 of the tapered waveguide, or between the bottom electrode 5 of the active device and the bottom electrode 13 of the tapered waveguide, or between the top electrode 6 of the tapered waveguide and its bottom electrode.

[0034] In a preferred embodiment, the electron blocking structure can utilize the intrinsic resistance of the top doped layer 7 and the bottom doped layer 9, or employ resistance formed by etching or ion implantation of the top doped layer 7 and the bottom doped layer 9 in different shapes. For example... Figure 2As shown, the electronic blocking structure can be implemented on the top doped layer 7, as shown in the first electronic blocking structure 4, i.e., resistor R3. The electronic blocking structure can also be implemented on the bottom doped layer 9, as shown in the second electronic blocking structure 12, i.e., resistor R4. At the same time, the first electronic blocking structure 4 and the second electronic blocking structure 12 can be respectively set inside the top doped layer 7 and the bottom doped layer 9. That is, various electronic blocking structures can be used individually or in combination. Here, R2, R3, and R4 together form the total resistance of the tapered waveguide 2. By adjusting the value of R1 / (R2+R3+R4), the current consumed by the tapered waveguide 2 can be adjusted, so that its impact on device performance is minimized. Similarly, the value of R1 / (R2+R3+R4) can be adjusted by those skilled in the art according to the design requirements of different devices.

[0035] In this embodiment, the electron blocking structure can utilize the intrinsic resistance of the top doped layer 7 and the bottom doped layer 9, or employ resistance formed by etching or ion implantation of the top doped layer 7 and the bottom doped layer 9 in different shapes, such as... Figure 2 As shown, the former is achieved by separating the top electrodes of the two waveguides. If necessary, ion implantation can also be used to remove the doping in the top material layer of the device to achieve a higher degree of isolation. The latter is achieved by a narrow channel structure with spacing. If the channel width is w, the channel length is h, the spacing width is Wg, and the intrinsic resistance of the doped layer is R, then the resistance of the increased electron barrier is Wg*R*h / w2.

[0036] Furthermore, the tapered waveguide 2 and the electronic barrier layer can be set on one side of the active device 1, or they can be symmetrically set on both sides of the active device 1. The setting method can be adapted by those skilled in the art according to the device design requirements.

[0037] Meanwhile, the bottom electrode 5 of the active device and the bottom electrode 13 of the tapered waveguide can be divided into two sections, with an electronic barrier structure set between the two sections.

[0038] In addition, the active device 1 can be any of the following devices: laser, amplifier, modulator, detector, attenuator, isolator; the bottom waveguide 10 can be any of the following devices: passive optical waveguide, modulator, isolator.

[0039] In a specific first embodiment, the present invention can be an electro-absorption modulated laser, wherein the active device 1 is a distributed feedback laser and the bottom waveguide 10 is an electro-absorption modulator.

[0040] In a specific second embodiment, the present invention can be a semiconductor optical amplifier, wherein the active device 1 is a semiconductor optical amplifier, and the bottom waveguide 10 is a passive optical waveguide or an electro-absorption modulator.

[0041] In a specific third embodiment, the present invention can be a detector in which the active device 1 is a waveguide detector and the bottom waveguide 10 is a passive optical waveguide.

[0042] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A laser with improved electro-optic efficiency, characterized in that, The device includes an active device, a tapered waveguide, a bottom waveguide, and a substrate. The bottom waveguide is disposed on the substrate. The active device and the tapered waveguide are arranged parallel to each other on the same layer and stacked perpendicularly to each other. The active device and the tapered waveguide have the same waveguide structure, and the active device is further provided with a top electrode and a bottom electrode, and the tapered waveguide is further provided with a top electrode and a bottom electrode. The active device is used to achieve photoelectric performance by applying a voltage or injecting current between the top electrode and the bottom electrode, and to transmit light propagating in the waveguide to the bottom waveguide through the tapered waveguide. It also includes an electronic blocking structure to increase the impedance of the tapered waveguide. The number of the electronic blocking structure is at least one, located between the top electrode of the active device and the top electrode of the tapered waveguide, or between the bottom electrode of the active device and the bottom electrode of the tapered waveguide, or between the top electrode of the tapered waveguide and its bottom electrode; the electronic blocking structure utilizes the intrinsic resistance of the top doped layer and the bottom doped layer, or uses resistance formed by etching or ion implantation of the top doped layer and the bottom doped layer in different shapes.

2. The laser with improved electro-optic efficiency according to claim 1, characterized in that, It also includes a top doped layer and a bottom doped layer; the top doped layer is disposed below the top electrode of the active device and the top electrode of the tapered waveguide, and forms an electrical contact with them; the bottom doped layer is disposed above the bottom waveguide, and is located below the bottom electrode of the active device and the bottom electrode of the tapered waveguide, and forms an electrical contact with them.

3. The laser with improved electro-optic efficiency according to claim 2, characterized in that, An active material layer is also provided between the bottom doped layer and the top doped layer.

4. The laser with improved electro-optic efficiency according to claim 2, characterized in that, The tapered waveguide and the active device are connected in parallel in the circuit.

5. The laser with improved electro-optic efficiency according to claim 2, characterized in that, The top doped layer and the bottom doped layer are p / n doped or n / p doped; the bottom electrode of the active device and the bottom electrode of the tapered waveguide are an integral structure.

6. The laser with improved electro-optic efficiency according to any one of claims 1 to 5, characterized in that, The active device is any one of the following: laser, amplifier, modulator, detector, attenuator, isolator.

7. The laser with improved electro-optic efficiency according to any one of claims 1 to 5, characterized in that, The bottom waveguide can be any of the following devices: passive optical waveguide, modulator, or isolator.

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