State adjustable dual gain optical structures and lasers on silicon substrates

Abstract

The application provides a silicon substrate adjustable double-gain optical structure and a laser, and relates to the technical field of lasers.The silicon substrate adjustable double-gain optical structure comprises a first reflective semiconductor optical amplifier, a second reflective semiconductor optical amplifier, a first phase modulator, a second phase modulator, a first optical coupler, a third phase modulator, a fourth phase modulator, a second optical coupler, a first port and a second port.The distribution ratio between reflected light and transmitted light is adjusted by adjusting the phase difference between the two reflective semiconductor optical amplifiers.The laser is configured by a plurality of silicon substrate state-adjustable double-gain optical structures configured as a half-transmission half-reflection device and selectively accessing optical amplifiers configured by the silicon substrate state-adjustable double-gain optical structures, the power of the laser is significantly improved, the chip structure is mixed and integrated, the laser does not contain an optical fiber, and the laser structure is more compact and stable.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser, more particularly, to a state-adjustable double-gain optical structure on silicon substrate and a laser. BACKGROUND

[0002] Silicon-based optoelectronic integrated technology has been widely and importantly applied in many fields such as optical communication, optical interconnection, optical sensing and the like, but the biggest bottleneck problem of silicon-based optoelectronic integrated technology is that laser cannot be directly generated in silicon material, and people have proposed various schemes to solve this problem, and the most suitable scheme at present is to mix and integrate III-V group light-emitting materials and silicon optical chips to manufacture a silicon-based external cavity laser. These lasers currently still have many problems to be solved, such as high-power laser, wavelength tunable laser and optical amplifier and the like.

[0003] In addition, in some optical systems that need to dynamically adjust the intensity distribution of optical signals according to actual working conditions, the traditional external cavity laser cannot conveniently adjust the proportion of transmitted light and reflected light, resulting in problems such as signal attenuation and interference in the transmission process of optical signals, and it is difficult to meet the demand of high-speed and stable data transmission. In the field of lasers, some applications need to accurately control the reflection and transmission ratio of laser to improve sensitivity and accuracy, and the limitation of the existing laser structure makes it difficult to achieve the ideal state in complex environments. Most of the existing tunable lasers realize the adjustment of wavelength or light intensity through mechanical tuning, temperature tuning and the like, but these adjustment methods have problems such as slow response speed, low adjustment precision and complex structure, and cannot meet the requirements of modern optoelectronic technology on high performance and flexible adjustment of lasers.

[0004] Therefore, a laser structure capable of flexibly adjusting laser power has become a technical problem to be solved in the current optoelectronic field. SUMMARY

[0005] In view of the problems in the background art, the present application provides a state-adjustable double-gain optical structure on silicon substrate and a laser, which solves the defects of the existing laser.

[0006] The technical solution of the present application to solve the above technical problems is as follows:

[0007] A state-adjustable double-gain optical structure on silicon substrate, characterized in that it comprises:

[0008] a first reflective semiconductor optical amplifier, a second reflective semiconductor optical amplifier, a first phase modulator, a second phase modulator, a first optical coupler, a third phase modulator, a fourth phase modulator, a second optical coupler, a first port and a second port,

[0009] The first end of the first reflective semiconductor optical amplifier is connected to the first end of the first phase modulator, the first end of the second reflective semiconductor optical amplifier is connected to the first end of the second phase modulator, the second end of the first phase modulator and the second end of the second phase modulator are respectively connected to the first end and the second end of the first optical coupler, the third end and the fourth end of the first optical coupler are respectively connected to the first end of the third phase modulator and the first end of the fourth phase modulator, the second end of the third phase modulator and the second end of the fourth phase modulator are respectively connected to the first end and the second end of the second optical coupler, the third end and the fourth end of the second optical coupler are respectively connected to the first port and the second port, the incident light enters from the first port, the reflected light is output from the first port, and the transmitted light is output from the second port.

[0010] The second end of the first reflective semiconductor optical amplifier and the second end of the second reflective semiconductor optical amplifier are both coated with a high reflection film, and the distribution ratio between the reflected light and the transmitted light is adjusted by adjusting the phase difference between the two reflective semiconductor optical amplifiers.

[0011] Preferably, the phase difference between the two reflective semiconductor optical amplifiers is The relationship between the reflected light electric field E Re and the transmitted light electric field E Tr is as follows:

[0012]

[0013] Wherein, E In is the incident light electric field, r A is the amplification factor of the first reflective semiconductor optical amplifier, i is the imaginary unit, κ is the coupling coefficient of the first optical coupler and the second optical coupler, t is the transmission coefficient of the first optical coupler and the second optical coupler, θ is the phase difference between the third phase modulator and the fourth phase modulator, and r is the gain ratio between the two reflective semiconductor optical amplifiers.

[0014] Preferably, the phase difference between the two reflective semiconductor optical amplifiers is adjusted, when the ratio of the reflected light electric field to the incident light electric field is 0, the first port does not output reflected light, and the optical structure is configured as an optical amplifier, when the ratio of the reflected light electric field to the incident light electric field is greater than 0 and less than 1, the optical structure is configured as a half-transmission half-reflection device.

[0015] A laser device, comprising: a half-transmission half-reflection device, and a first reflective device, the first port of the half-transmission half-reflection device is connected to the first reflective device; wherein the first reflective device is a full reflector or a wavelength tunable reflector or a half reflector.

[0016] Preferably, further comprising a second reflecting device, the second port of the half-transmission half-reflection device is connected to one end of the second reflecting device, and the other end of the second reflecting device is the output port of the laser; wherein the second reflecting device is a wavelength tunable reflector or a half-reflector.

[0017] A laser, comprising: two half-transmission half-reflection devices, wherein the first port of one of the half-transmission half-reflection devices is connected to the first port of the other half-transmission half-reflection device, and the incident light of one of the half-transmission half-reflection devices enters the other half-transmission half-reflection device as incident light after being reflected by the two reflective semiconductor optical amplifiers inside.

[0018] Preferably, further comprising an optical amplifier, the first port of the optical amplifier is connected to the first port of one of the half-transmission half-reflection devices, and the second port of the optical amplifier is connected to the first port of the other half-transmission half-reflection device.

[0019] Preferably, further comprising a tunable filter, the first end of the tunable filter is connected to the first port of one of the half-transmission half-reflection devices, and the second end of the tunable filter is connected to the first port of the other half-transmission half-reflection device.

[0020] Preferably, the tunable filter is a double-micro-ring structure, and the laser is configured as a tunable laser.

[0021] The beneficial effects of the present application are:

[0022] (1) The mutual interaction relationship of the two reflective semiconductor optical amplifiers is utilized, and a unique optical structure is constructed by cooperating with the first phase modulator and the second phase modulator directly connected thereto, so that the phase relationship between the two can be precisely adjusted;

[0023] (2) When the ratio of the reflected optical field to the incident optical field is 0, the optical structure can be configured as an optical amplifier to realize effective amplification and output of optical signals; when the ratio is in the interval greater than 0 and less than 1, the optical structure is configured as a half-transmission half-reflection device, which facilitates the expansion of the structure and widens the application range;

[0024] (3) According to the phase and gain ratio between the two reflective semiconductor optical amplifiers, the light splitting ratio of the first optical coupler and the second optical coupler, and the phase difference between the third phase modulator and the fourth phase modulator, the reflected optical field and the transmitted optical field are calculated to realize flexible adjustment of the proportion of transmitted light and reflected light;

[0025] (4) The half-transmission half-reflection device configured by the state-adjustable double-gain optical structure on the silicon substrate is combined with a reflector to form a laser, so that the intracavity Q value of the laser is adjustable, and the laser power of each end surface is also adjustable.

[0026] (5) The laser is configured by using the semi-transmissive-semireflective device configured by the state-adjustable dual-gain optical structure on the silicon substrate and the selectively accessed optical amplifier configured by the state-adjustable dual-gain optical structure on the silicon substrate, the power of the laser is significantly improved, the hybrid integrated chip structure is free of optical fiber, and the laser structure is more compact and stable. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to make the present application more easily understood, the present application will be described in more detail by referring to the specific embodiments shown in the drawings. These drawings only depict typical embodiments of the present application and should not be considered as limiting the scope of the present application.

[0028] Figure 1 is a structural schematic diagram of the state-adjustable dual-gain optical structure on the silicon substrate provided by an embodiment of the present application;

[0029] Figure 2 is a phase adjustment schematic diagram of the state-adjustable dual-gain optical structure on the silicon substrate provided by an embodiment of the present application;

[0030] Figure 3 is a structural schematic diagram of the laser provided by an embodiment of the present application;

[0031] Figure 4 is another structural schematic diagram of the laser provided by another embodiment of the present application;

[0032] Figure 5 is another structural schematic diagram of the laser provided by another embodiment of the present application;

[0033] Figure 6 is another structural schematic diagram of the laser provided by another embodiment of the present application;

[0034] Figure 7 is another structural schematic diagram of the laser provided by another embodiment of the present application.

[0035] Reference Signs:

[0036] 100 - state-adjustable dual-gain optical structure on the silicon substrate, 110 - reflective semiconductor optical amplifier pair, 121a - first phase adjuster, 121b - second phase adjuster, 123a - first optical coupler, 122a - third phase adjuster, 122b - fourth phase adjuster, 123b - second optical coupler, 120 - silicon substrate, 100-R - semi-transmissive-semireflective device, 100-A - optical amplifier, 210 - first reflective device, 220 - second reflective device, 500 - tunable filter. DETAILED DESCRIPTION

[0037] Embodiments of the present application are described herein with reference to the accompanying drawings, of which the embodiments are not intended to be limiting, and the embodiments and technical features described in the embodiments can be combined with each other without conflict, if necessary, under the premise that the same parts are denoted by the same reference numerals, so that those skilled in the art can better understand and implement the present application. All other embodiments obtained by those skilled in the art without creative labor based on the embodiments of the present application are within the scope of protection of the present application.

[0038] The present application provides a state-adjustable dual-gain optical structure on a silicon substrate. Please refer to Figure 1 , Figure 1 is a structural schematic diagram of the state-adjustable dual-gain optical structure on a silicon substrate provided by the embodiments of the present application.

[0039] Please refer to Figure 1 In the embodiments of the present application, the state-adjustable dual-gain optical structure on a silicon substrate 100 includes a reflective semiconductor optical amplifier pair 110 composed of two reflective semiconductor optical amplifiers, a first phase modulator 121a, a second phase modulator 121b, a first optical coupler 123a, a third phase modulator 122a, a fourth phase modulator 122b, and a second optical coupler 123b. The first ends of the two reflective semiconductor optical amplifiers are respectively connected to the first ends of the first phase modulator 121a and the second phase modulator 121b. The second ends of the first phase modulator 121a and the second phase modulator 121b are respectively connected to the first end and the second end of the first optical coupler 123a. The third end and the fourth end of the first optical coupler 123a are respectively connected to the first end of the third phase modulator 122a and the first end of the fourth phase modulator 122b. The second end of the third phase modulator 122a and the second end of the fourth phase modulator 122b are respectively connected to the first end and the second end of the second optical coupler 123b. The third end and the fourth end of the second optical coupler 123b are respectively connected to the first port and the second port. The incident light In enters from the first port, and the reflected light Re is output from the first port. The second port is used to output the transmitted light Tr.

[0040] The incident light In enters from the first port, is split by the second optical coupler 123b, is phase-modulated by the third phase modulator 122a and the fourth phase modulator 122b, is combined by the first optical coupler 123a, enters the reflective semiconductor optical amplifier pair 110 formed by two reflective semiconductor optical amplifiers, and is phase-modulated by the first phase modulator 121a and the second phase modulator 121b. The ends of the two reflective semiconductor optical amplifiers away from the first phase modulator 121a and the second phase modulator 121b are coated with high-reflection films. The reflected light is sequentially phase-modulated by the first phase modulator 121a, the second phase modulator 121b, the first optical coupler 123a, the third phase modulator 122a, and the fourth phase modulator 122b, and is output as reflected light Re and transmitted light Tr after passing through the second optical coupler 123b.

[0041] Figure 2 is a phase adjustment schematic diagram of the state-adjustable dual-gain optical structure on a silicon substrate provided by the embodiment of the present application, referring to Figure 2 , the two reflective semiconductor optical amplifiers have a phase difference The first phase modulator 121a and the second phase modulator 121b are directly connected and cooperated to construct a unique optical structure, so as to accurately adjust the phase relationship between the two reflective semiconductor optical amplifiers. Re The relationship between the reflected light electric field E Tr and the transmitted light electric field E

[0042]

[0043]

[0044] wherein, E In is an incident light electric field, r A is an amplification multiple of one of the reflective semiconductor optical amplifiers in the reflective semiconductor optical amplifier pair 110, i is an imaginary unit, κ is a coupling coefficient of the first optical coupler 123a and the second optical coupler 123b, t is a transmission coefficient of the first optical coupler 123a and the second optical coupler 123b, θ is a phase difference between the third phase modulator 122a and the fourth phase modulator 122b, and r is a gain ratio between the two reflective semiconductor optical amplifiers.

[0045] It can be seen that, by adjusting the phase difference between the two reflective semiconductor optical amplifiers, the distribution ratio between the reflected light and the transmitted light can be adjusted. When the ratio of the reflected light electric field to the incident light electric field is 0, the first port does not output reflected light, at this time, only transmitted light is output without reflected light, which is equivalent to an optical amplifier, and the corresponding optical structure is configured as an optical amplifier, denoted as 100-A. When the ratio of the reflected light electric field to the incident light electric field is greater than 0 and less than 1, the optical structure is configured as a half-transmission half-reflection device, denoted as 100-R.

[0046] It is worth mentioning that the gain ratio between the two reflective semiconductor optical amplifiers, the light splitting ratio of the first optical coupler and the second optical coupler, and the phase difference between the third phase modulator and the fourth phase modulator can be set as a constant value, and the reflected light field and the transmitted light field can be calculated according to the phase difference between the two reflective semiconductor optical amplifiers, so that the flexible adjustment of the ratio of the transmitted light and the reflected light can be realized. The ratio of the reflected light and the transmitted light can also be adjusted according to the phase and gain ratio between the two reflective semiconductor optical amplifiers, the light splitting ratio of the first optical coupler and the second optical coupler, and the phase difference between the third phase modulator and the fourth phase modulator, so that the flexible adjustment of the ratio of the transmitted light and the reflected light can be realized. When the ratio of the reflected light field to the incident light field is 0, the optical structure can be configured as an optical amplifier to realize effective amplification output of the optical signal; when the ratio is in the interval greater than 0 and less than 1, the optical structure is configured as a half-transmission half-reflection device, which is convenient for realizing structure expansion and widening the application range.

[0047] Figure 3 is a structural schematic diagram of a laser provided by an embodiment of the present application, referring to Figure 3 The laser comprises a half-transmission half-reflection device 100-R and a first reflective device 210, and the first port of the half-transmission half-reflection device 100-R is connected to the first reflective device 210; wherein the first reflective device is a full reflector or a wavelength tunable reflector or a half reflector.

[0048] The first port of the half-transmission half-reflection device 100-R inputs incident light, and the incident light enters the optical structure and is finally output as reflected light at the first port after being reflected by the two reflective semiconductor optical amplifiers, and is output as transmitted light at the second port. The output reflected light can be reflected by the first reflective device 210 as incident light and return to the half-transmission half-reflection device 100-R, and multiple reflections form a resonant cavity of the laser. The first reflective device 210 is a full reflector or a wavelength tunable reflector or a half reflector, which can all reflect the output reflected light back to the half-transmission half-reflection device.

[0049] The present application utilizes the half-transmission half-reflection device configured by the state-adjustable double-gain optical structure on the silicon substrate, and combines the first reflective device to form the laser, so that the cavity Q value of the laser is adjustable, and the laser power of each end surface is also adjustable. At the same time, not only the laser power is improved, but also the output light power is adjustable.

[0050] Figure 4 is another structural schematic diagram of a laser provided by another embodiment of the present application, referring to Figure 4The second reflective device 220 is a wavelength tunable reflector or a half reflector, and the other end of the second reflective device 220 is an output port of the laser.

[0051] Figure 5 is another structural schematic diagram of the laser provided by another embodiment of the present application, referring to Figure 5 The laser comprises two half-transmission half-reflectors 100-R, the first port of the first half-transmission half-reflector is connected to the first port of the second half-transmission half-reflector, and the incident light of the first half-transmission half-reflector enters the second half-transmission half-reflector as incident light after being reflected by the two reflective semiconductor optical amplifiers inside the first half-transmission half-reflector, that is, the reflected light of the first half-transmission half-reflector is the incident light of the second half-transmission half-reflector, and the reflected light of the second half-transmission half-reflector is the incident light of the first half-transmission half-reflector. The light forms a resonant cavity after multiple reflections, the cavity Q value of the laser is adjustable, and the laser power of each end surface is also adjustable. At the same time, four reflective semiconductor optical amplifiers are included in one laser structure, and the laser power is increased by four times, which not only realizes the increase of the laser power, but also realizes the adjustable output light power.

[0052] In another embodiment, referring to Figure 6 An optical amplifier 100-A is further connected between the two half-transmission half-reflectors 100-R, the first port of the optical amplifier 100-A is connected to the first port of the first half-transmission half-reflector, and the second port of the optical amplifier 100-A is connected to the first port of the second half-transmission half-reflector; a plurality of optical amplifiers 100-A can be added inside the laser, and the laser power is further amplified.

[0053] In another embodiment, referring to Figure 7 An optical amplifier 100-A is further connected between the two half-transmission half-reflectors 100-R, the first port of the optical amplifier 100-A is connected to the first port of the first half-transmission half-reflector, and the second port of the optical amplifier 100-A is connected to the first port of the second half-transmission half-reflector; a plurality of optical amplifiers 100-A can be added inside the laser, and the laser power is further amplified.

[0054] The application utilizes a plurality of silicon substrate state-adjustable double-gain optical structures configured into a semi-transmissive and semi-reflective device and selectively accesses optical amplifiers configured with the silicon substrate state-adjustable double-gain optical structures to form a laser, the power of the laser is significantly improved, the mixed integrated chip structure does not contain an optical fiber, and the laser structure is more compact and stable. The laser structure formed by a plurality of silicon substrate state-adjustable double-gain optical structures contains a plurality of reflective semiconductor optical amplifiers, the light of the plurality of reflective semiconductor optical amplifiers is mutually coupled and coherent, and is not simply superimposed. Based on the mixed integrated chip laser structure, the laser structure can be further expanded into a laser radar, a laser gyroscope and the like.

[0055] The embodiments in the application are described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and the related parts can be referred to the method part.

[0056] The above-described embodiments are only the preferred specific embodiments of the application, and the phrases "in an embodiment", "in another embodiment", "in yet another embodiment" or "in other embodiments" in the specification can refer to one or more of the same or different embodiments according to the present disclosure. The usual changes and replacements made by those skilled in the art within the scope of the technical scheme of the application should be included in the protection scope of the application.

Claims

1. A laser, characterized in that, include: A state-tunable dual-gain optical structure and a first reflective device on a silicon substrate; The on-chip tunable dual-gain optical structure includes: a first reflective semiconductor optical amplifier, a second reflective semiconductor optical amplifier, a first phase modulator, a second phase modulator, a first optical coupler, a third phase modulator, a fourth phase modulator, a second optical coupler, a first port, and a second port. The first terminal of the first reflective semiconductor optical amplifier is connected to the first terminal of the first phase modulator. The first terminal of the second reflective semiconductor optical amplifier is connected to the first terminal of the second phase modulator. The second terminals of the first and second phase modulators are respectively connected to the first and second terminals of the first optical coupler. The third and fourth terminals of the first optical coupler are respectively connected to the first terminal of the third phase modulator and the first port. The first end of the four phase modulators, the second ends of the third and fourth phase modulators are respectively connected to the first and second ends of the second optical coupler. The third and fourth ends of the second optical coupler are respectively connected to the first port and the second port. Incident light enters from the first port, reflected light exits from the first port, and the second port is used to output transmitted light. The second ends of the first and second reflective semiconductor optical amplifiers are both coated with high-reflectivity films. The distribution ratio between the reflected light and the transmitted light is adjusted by adjusting the phase difference between the two reflective semiconductor optical amplifiers. The phase difference between the two reflective semiconductor optical amplifiers... With the reflected photoelectric field E Re and transmitted photoelectric field E Tr The relationship is as follows: ， ， Among them, E In For the incident photoelectric field, r A Let i be the amplification factor of the first reflective semiconductor optical amplifier, where i is the imaginary unit. Let be the coupling coefficient between the first optical coupler and the second optical coupler, and t be the transmission coefficient between the first optical coupler and the second optical coupler. The phase difference between the third phase modulator and the fourth phase modulator is r, and the gain ratio between the two reflective semiconductor optical amplifiers is r. The ratio of the reflected photoelectric field to the incident photoelectric field is greater than 0 and less than 1. The state-tunable dual-gain optical structure on the silicon substrate is configured as a transmissive and reflective device. The first port of the state-tunable dual-gain optical structure on the silicon substrate is connected to the first reflective device; wherein the first reflective device is a total reflector, a wavelength-tunable reflector, or a half reflector.

2. The laser according to claim 1, characterized in that, It also includes a second reflective device, wherein the second port of the state-tunable dual-gain optical structure on the silicon substrate is connected to one end of the second reflective device, and the other end of the second reflective device is the output port of the laser; wherein the second reflective device is a wavelength-tunable reflector or a half-reflector.

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