Bistable-state-interval-adjustable semiconductor laser

Abstract

The utility model belongs to the technical field of semiconductor lasers, and provides a semiconductor laser with an adjustable bistable interval. The side gain region is formed at any position of the side of the ridge gain region, when forward current is applied to the side gain region, the output optical power of the laser can be effectively improved by utilizing the gain amplification characteristic of the side gain region, and the optical output power shows an anticlockwise hysteresis loop bistable state along with the rising and falling process of the current of the ridge gain region, so that the output optical power of the laser is improved. The conversion ratio of the bistable switch is increased along with the increase of the current of the side gain region; a side edge absorption area is formed at any position of the side edge of a ridge waveguide saturation absorption area, the saturation absorption characteristic of the side edge absorption area is utilized, the reverse bias voltage of the ridge waveguide saturation absorption area and the side edge absorption area is regulated, and the current range of a bistable area is adjustable. And the change of the reverse bias voltage of the side absorption region compensates and regulates the bistable output range. Therefore, the bistable characteristic of the output light can be optimized, and the bistable interval is controllable.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor lasers, in particular to a semiconductor laser with adjustable bistable interval. Background Art

[0002] Semiconductor lasers have the advantages of small volume, low power consumption and easy integration. Bistable semiconductor lasers show great application potential in optical storage, optical switches, optical logic gates, optical sensing and measurement due to their unique non-linear dynamic characteristics.

[0003] At present, the main methods to achieve adjustable bistable intervals are as follows: one is optical feedback regulation. By introducing appropriate optical feedback devices, such as mirrors and fiber couplers, outside the semiconductor laser, and adjusting the intensity and phase of the optical feedback, the width and position of the bistable interval can be changed. However, this regulation method will inevitably increase the volume of the semiconductor laser, which is not conducive to the integration of microcircuits. The second is temperature regulation. By designing a precise temperature control system to affect the distribution and mobility of carriers inside the laser, and then improving the gain and loss characteristics of the laser. This regulation method requires high costs and technical support. The third is injection current regulation. By precisely controlling the injection current of the semiconductor laser, the bistable interval can be shifted to a higher or lower power direction. This regulation method is the simplest and feasible. However, existing semiconductor bistable lasers are limited by their structures and fabrication processes, and the controllable range is restricted.

[0004] Based on this, the utility model designs a semiconductor laser device with an adjustable bistable interval by a simple injection current regulation method, which is very suitable for the current development needs of high-density optical integration, optical interconnection, etc. Summary of the Utility Model

[0005] Aiming at the above problems, the utility model provides a semiconductor laser with an adjustable bistable interval, which can solve the problems of insufficient output power and insufficient adjustable range of existing semiconductor bistable lasers.

[0006] To solve the above technical problems, the technical solution adopted by the utility model is: a semiconductor laser with an adjustable bistable interval, which adopts a ridge waveguide structure. On the ridge of the ridge waveguide structure, a ridge gain region, a ridge waveguide electrical isolation region and a ridge waveguide saturable absorption region are sequentially formed. The ridge waveguide electrical isolation region is arranged between the ridge gain region and the ridge waveguide saturable absorption region to separate the two. At any position on the side of the ridge gain region, a side gain region is arranged, and a forward current is applied to the side gain region to form gain. At any position on the side of the ridge waveguide saturable absorption region, a side absorption region is arranged, and a reverse bias signal is applied to the ridge waveguide saturable absorption region and the side absorption region to form saturable absorption.

[0007] Preferably, planar electrodes are provided on the ridge gain region, the ridge waveguide saturable absorption region, the side gain region, and the side absorption region, and the planar electrodes on the ridge gain region, the ridge waveguide saturable absorption region, the side gain region, and the side absorption region are not connected to each other.

[0008] Preferably, an anti-reflection film-coated light-emitting end face is provided on the end face of the ridge gain region at the end away from the ridge waveguide electrical isolation region along the length direction; an optical dielectric film with a high reflectivity is provided on the end face of the ridge waveguide saturable absorption region at the end away from the ridge waveguide electrical isolation region, and both this end face and the light-emitting end face are perpendicular to the length direction of the ridge gain region.

[0009] Preferably, a first side electrical isolation region is formed at any position on one or both sides of the ridge gain region, the side gain region is provided on the side of the first side electrical isolation region away from the ridge gain region, the first side electrical isolation region and the side gain region are prepared by laminating in a direction perpendicular to the length direction of the ridge gain region, and both the side electrical isolation region and the side gain region are parallel to the length direction of the ridge gain region.

[0010] Preferably, a second side electrical isolation region is formed at any position on one or both sides of the ridge waveguide saturable absorption region, the side absorption region is provided on the side of the second side electrical isolation region away from the ridge waveguide saturable absorption region, the second side electrical isolation region and the side absorption region are prepared by laminating in a direction perpendicular to the length direction of the ridge waveguide saturable absorption region, and both the second side electrical isolation region and the side absorption region are parallel to the length direction of the ridge waveguide saturable absorption region.

[0011] Preferably, the side gain region and the side absorption region can be prepared symmetrically or asymmetrically distributed on both sides of the ridge waveguide structure.

[0012] Preferably, the ridge waveguide electrical isolation region, the first side electrical isolation region on the ridge gain region, and the second side electrical isolation region on the ridge waveguide saturable absorption region are all formed by wet and dry etching methods or ion implantation methods.

[0013] Preferably, the length of the ridge gain region is greater than the total length of the ridge waveguide electrical isolation region and the ridge waveguide saturable absorption region, the lengths of the first side electrical isolation region and the side gain region are both less than the length of the ridge gain region, and the lengths of the second side electrical isolation region and the side absorption region are both less than the length of the ridge waveguide saturable absorption region.

[0014] Preferably, the length of the first side electrical isolation region along the length direction of the ridge gain region is greater than or equal to the length of the side gain region along the length direction of the ridge gain region, and the length of the second side electrical isolation region along the length direction of the ridge waveguide saturable absorption region is greater than or equal to the length of the side absorption region along the length direction of the ridge waveguide saturable absorption region.

[0015] Preferably, the etching depths of the ridge gain region and the side gain region are the same during the chip manufacturing process, and the etching depths of the ridge waveguide saturable absorption region and the side absorption region are the same during the chip manufacturing process.

[0016] As can be seen from the above description of the structure of the present invention, compared with the prior art, the present invention has the following advantages:

[0017] The present invention forms a side gain region at any position on the side of the ridge gain region. When a forward current is applied to the side gain region, the output optical power of the laser can be effectively increased by utilizing the gain amplification characteristics of the side gain region. As the current in the ridge gain region rises and falls, the optical output power exhibits bistability with a counterclockwise "hysteresis loop". As the current in the side gain region increases, the bistable switching ratio increases; a side absorption region is formed at any position on the side of the ridge waveguide saturable absorption region. By utilizing the saturable absorption characteristics of the side absorption region and regulating the reverse bias voltages on the ridge waveguide saturable absorption region and the side absorption region, the current range of the bistable region can be adjusted, and the change in the reverse bias voltage on the side absorption region compensates and regulates the bistable output range. Therefore, when the current in the ridge gain region and the voltage in the ridge waveguide saturable absorption region are kept at certain values, by only adjusting the current in the side gain region and the bias voltage in the side absorption region, the bistable characteristics of the output light can be optimized, making the bistable interval controllable. Description of the Drawings

[0018] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0019] Figure 1 is a ridge waveguide schematic diagram of the present invention with a side gain region and a side absorption region respectively prepared on one side of the ridge gain region and the ridge waveguide saturable absorption region;

[0020] Figure 2 is a ridge waveguide schematic diagram of the present invention with a side gain region and a side absorption region respectively prepared on both sides of the ridge gain region and the ridge waveguide saturable absorption region. Detailed Description of the Invention

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. However, those skilled in the art are aware that the present invention is not limited to the drawings and the following embodiments.

[0022] A semiconductor laser with adjustable bistable interval proposed by the utility model is successively composed of a lower electrode, a substrate, a lower separate confinement layer, a lower waveguide layer, an active region, an upper waveguide layer, an upper separate confinement layer, a cover layer, a SiO₂ current isolation layer, and an upper electrode. The laser is formed by processes such as lithography, etching, growing a dielectric insulating layer, opening an electrode window, and sputtering a metal chip structure.

[0023] The laser adopts a ridge waveguide structure, forms a side gain region at any position on the side of the ridge gain region, and forms a side absorption region at any position on the side of the ridge waveguide saturable absorption region. By electrically pumping the side gain region / side absorption region, the bistable characteristics of the output light are optimized, thereby regulating the bistable interval.

[0024] The following describes the specific setting positions of the side adjustable gain / absorption regions in conjunction with the drawings.

[0025] Embodiment 1

[0026] Figure 1 An example of a ridge waveguide is given in which a side gain region is formed at any position on one side of the ridge gain region, and a side absorption region is formed at any position on one side of the ridge absorption region.

[0027] On the ridge of the ridge waveguide structure, a ridge gain region 11, a ridge waveguide electrical isolation region 12, and a ridge waveguide saturable absorption region 13 are successively formed. Among them, the ridge waveguide electrical isolation region 12 separates the ridge gain region 11 and the ridge waveguide saturable absorption region 13 to form electrical isolation, but not optical isolation.

[0028] The ridge gain region 11 is strip-shaped, the ridge waveguide electrical isolation region 12 is located at one end of the ridge gain region 11 along the length direction, the opposite direction of the ridge gain region 11 along the length direction is the light output end face, and an antireflection film is plated on the light output end face; an optical dielectric film with a high reflectivity is plated on the end face at the ridge waveguide saturable absorption region 13 end.

[0029] At any position on one side of the ridge gain region 11, a first side electrical isolation region 121 and a side gain region 111 are prepared. The first side electrical isolation region 121 and the side gain region 111 are laminated and prepared in a direction perpendicular to the length direction of the ridge gain region 11. At any position on one side of the ridge waveguide saturable absorption region 13, a second side electrical isolation region 122 and a side absorption region 131 are prepared. The second side electrical isolation region 122 and the side absorption region 131 are laminated and prepared in a direction perpendicular to the length direction of the ridge waveguide saturable absorption region 13. The first side electrical isolation region 121, the second side electrical isolation region 122, the side gain region 111, and the side absorption region 131 are all parallel to the length direction of the ridge waveguide structure. The side gain region 111 and the side absorption region 131 can be prepared on the same side or different sides of the ridge waveguide structure.

[0030] Among them, the length of the first side electrical isolation region 121 along the length direction of the ridge gain region 11 is greater than or equal to the length of the side gain region 111 along the length direction of the ridge gain region 11 to achieve better electrical isolation. The lengths of the first side electrical isolation region 121 and the side gain region 111 along the length direction of the ridge gain region 11 are both less than the length of the ridge gain region 11. The length of the second side electrical isolation region 122 along the length direction of the ridge waveguide saturable absorption region 13 is greater than or equal to the length of the side absorption region 131 along the length direction of the ridge waveguide saturable absorption region 13. The lengths of the second side electrical isolation region 122 and the side absorption region 131 along the length direction of the ridge waveguide saturable absorption region 13 are both less than the length of the ridge waveguide saturable absorption region 13.

[0031] The ridge waveguide electrical isolation region 12, the first side electrical isolation region 121, and the second side electrical isolation region 122 are all formed by processes such as wet and dry etching or ion implantation, so that there is a resistance value of several hundred to several thousand ohms between the ridge gain region 11 and the ridge waveguide saturable absorption region 13, between the ridge gain region 11 and the side gain region 111, and between the ridge waveguide saturable absorption region 13 and the side absorption region 131, ensuring a high degree of electrical isolation, but not optical isolation.

[0032] Planar electrodes are provided on the ridge gain region 11, the ridge waveguide saturable absorption region 13, the side gain region 111, and the side absorption region 131, and the planar electrodes of the ridge gain region 11, the ridge waveguide saturable absorption region 13, the side gain region 111, and the side absorption region 131 are not connected to each other.

[0033] The bias voltages applied to the ridge waveguide saturable absorption region 13 and the side absorption region 131 can be the same or different.

[0034] When the laser operates, a forward current is applied to the ridge gain region 11 to form gain, and a reverse bias voltage is applied to the ridge waveguide saturable absorption region 13 to form a saturable absorber. As the current in the ridge gain region 11 rises and falls, the optical output power exhibits bistability of a counterclockwise "hysteresis loop". The bistable switching ratio is optimized by increasing the current on the side gain region 111, and the current range of the bistable region is finely tuned by regulating the reverse bias voltage on the side absorption region 131, so as to achieve the purpose of controllable bistable interval.

[0035] Embodiment 2

[0036] The difference between this Embodiment 2 and Embodiment 1 is that in Embodiment 1, the side electrical isolation region, the side gain region, and the side absorption region are only set at an arbitrary position on one side of the ridge waveguide structure, while in this Embodiment 2, the side electrical isolation region, the side gain region, and the side absorption region are set at arbitrary positions on both sides of the ridge waveguide structure. Figure 2Examples are given of forming a side gain region at any position on both sides of the ridge gain region and forming a side absorption region at any position on both sides of the ridge waveguide saturation absorption region.

[0037] A ridge gain region 11, a ridge waveguide electrical isolation region 12, and a ridge waveguide saturation absorption region 13 are sequentially formed on the ridge of the ridge waveguide structure. Among them, the ridge waveguide electrical isolation region 12 separates the ridge gain region 11 and the ridge waveguide saturation absorption region 13 to form electrical isolation, but not optical isolation.

[0038] The ridge gain region 11 is strip-shaped. The ridge waveguide electrical isolation region 12 is located at one end of the ridge gain region 11 along the length direction. The opposite direction of the ridge gain region 11 along the length direction is the light-emitting end face, and an antireflection film is coated on the light-emitting end face; an optical dielectric film with a high reflectivity is coated on the end face at the ridge waveguide saturation absorption region 13 end.

[0039] Side gain regions 111 and first side electrical isolation regions 121 are provided at any positions on both sides of the ridge gain region 11. The side gain regions 111 are connected to the ridge gain region 11 through the first side electrical isolation regions 121. The first side electrical isolation regions 121 and the side gain regions 111 are prepared by laminating in a direction perpendicular to the length direction of the ridge gain region 11. Second side electrical isolation regions 122 and side absorption regions 131 are prepared at any positions on both sides of the ridge waveguide saturation absorption region 13. The side absorption regions 131 are connected to the ridge waveguide saturation absorption region 13 through the second side electrical isolation regions 122. The second side electrical isolation regions 122 and the side absorption regions 131 are prepared by laminating in a direction perpendicular to the length direction of the ridge waveguide saturation absorption region 13. The first side electrical isolation regions 121, the second side electrical isolation regions 122, the side gain regions 111, and the side absorption regions 131 are all parallel to the length direction of the ridge waveguide structure. The side gain regions and the side absorption regions can be prepared symmetrically or asymmetrically distributed on both sides of the ridge waveguide structure.

[0040] Among them, the length of the first side electrical isolation region 121 along the length direction of the ridge gain region 11 is greater than or equal to the length of the side gain region 111 along the length direction of the ridge gain region 11 to achieve better electrical isolation. The lengths of the first side electrical isolation region 121 and the side gain region 11 along the length direction of the ridge gain region 11 are both less than the length of the ridge gain region 11. The length of the second side electrical isolation region 122 along the length direction of the ridge waveguide saturation absorption region 13 is greater than or equal to the length of the side absorption region 131 along the length direction of the ridge waveguide saturation absorption region 13 to achieve better electrical isolation. The lengths of the second side electrical isolation region 122 and the side absorption region 131 along the length direction of the ridge waveguide saturation absorption region 13 are both less than the length of the ridge waveguide saturation absorption region 1.

[0041] Planar electrodes are provided on the ridge gain region 11, the ridge waveguide saturable absorption region 13, the side gain region 111, and the side absorption region 131, and the planar electrodes on the ridge gain region 11, the ridge waveguide saturable absorption region 13, the side gain region 111, and the side absorption region 131 are not connected to each other.

[0042] The bias voltages applied to the ridge waveguide saturable absorption region 13 and the side absorption region 131 may be the same or different. The sizes of the side gain regions 111 prepared on both sides of the ridge gain region 11 may be the same or different. The sizes of the side absorption regions 131 prepared on both sides of the ridge waveguide saturable absorption region 13 may be the same or different.

[0043] The same parts as those in the foregoing embodiments will not be described again.

[0044] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A semiconductor laser with adjustable bistable range, characterized in that: The semiconductor laser adopts a ridge waveguide structure, and a ridge gain region, a ridge waveguide conductive isolation region and a ridge waveguide saturation absorption region are sequentially formed on the ridge of the ridge waveguide structure, and the ridge waveguide conductive isolation region is arranged between the ridge gain region and the ridge waveguide saturation absorption region to separate the two; a side gain region is arranged at any position on the side of the ridge gain region, and a forward current is applied to the side gain region to form gain; a side absorption region is arranged at any position on the side of the ridge waveguide saturation absorption region, and a reverse bias signal is applied to the ridge waveguide saturation absorption region and the side absorption region to form saturation absorption.

2. The semiconductor laser with a bistable range adjustable according to claim 1, characterized in that: Planar electrodes are arranged on the ridge gain region, ridge waveguide saturated absorption region, side gain region and side absorption region, and the planar electrodes on the ridge gain region, ridge waveguide saturated absorption region, side gain region and side absorption region are not connected to each other.

3. The semiconductor laser with bistable range adjustable according to claim 1, characterized in that: A light-emitting end face coated with an anti-reflection film is arranged on the end face of one end of the ridge gain region away from the ridge wave conductive isolation region along the length direction; an optical medium film coated with a high reflectivity is arranged on the end face of one end of the ridge waveguide saturation absorption region away from the ridge wave conductive isolation region, and both the end face and the light-emitting end face are perpendicular to the length direction of the ridge gain region.

4. The semiconductor laser with bistable range adjustable according to claim 1, characterized in that: A first side electrical isolation region is formed at any position on one side or both sides of the ridge gain region, and the side gain region is arranged on a side of the first side electrical isolation region away from the ridge gain region. The first side electrical isolation region and the side gain region are stacked in a direction perpendicular to the length direction of the ridge gain region, and the side electrical isolation region and the side gain region are both parallel to the length direction of the ridge gain region.

5. The semiconductor laser with bistable range adjustable according to claim 1, characterized in that: A second side electrical isolation region is formed at any position on one side or both sides of the ridge waveguide saturated absorption region, and the side absorption region is arranged on a side of the second side electrical isolation region away from the ridge waveguide saturated absorption region, and the second side electrical isolation region and the side absorption region are stacked in a direction perpendicular to the length direction of the ridge waveguide saturated absorption region, and the second side electrical isolation region and the side absorption region are both parallel to the length direction of the ridge waveguide saturated absorption region.

6. The semiconductor laser with bistable range adjustable according to claim 1, characterized in that: The side gain region and the side absorption region can be prepared by symmetrical or asymmetrical distribution on both sides of the ridge waveguide structure.

7. The semiconductor laser with bistable range adjustable according to claim 1, characterized in that: The ridge waveguide conductive isolation region, the first side electrical isolation region on the ridge gain region and the second side electrical isolation region on the ridge waveguide saturated absorption region are all formed by dry and wet etching methods or ion implantation methods.

8. The semiconductor laser with bistable range adjustable according to claim 7, characterized in that: The length of the ridge gain zone is greater than the total length of the ridge waveguide conductive isolation zone and the ridge waveguide saturation absorption zone, the lengths of the first side electrical isolation zone and the side gain zone are both shorter than the length of the ridge gain zone, and the lengths of the second side electrical isolation zone and the side absorption zone are both shorter than the length of the ridge waveguide saturation absorption zone.

9. The semiconductor laser with bistable range adjustable according to claim 8, characterized in that: The length of the first side electrical isolation region along the length direction of the ridge gain region is greater than or equal to the length of the side gain region along the length direction of the ridge gain region, and the length of the second side electrical isolation region along the length direction of the ridge waveguide saturated absorption region is greater than or equal to the length of the side absorption region along the length direction of the ridge waveguide saturated absorption region.

10. The semiconductor laser with bistable range adjustable according to claim 1, characterized in that: The etching depths of the ridge gain region and the side gain region during the tape-out process are the same, and the etching depths of the ridge waveguide saturated absorption region and the side absorption region during the tape-out process are the same.

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