State-adjustable double-gain optical structure on silicon substrate and laser

Abstract

The invention provides an adjustable double-gain optical structure on a silicon substrate and a laser, and relates to the technical field of lasers. The adjustable double-gain optical structure on the silicon substrate comprises a first reflection type semiconductor optical amplifier, a second reflection type 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 proportion between the reflected light and the transmitted light is adjusted by adjusting the phase difference between the two reflective semiconductor optical amplifiers. A laser is formed by utilizing a semi-transparent semi-reflecting device configured by a plurality of state-adjustable double-gain optical structures on a silicon substrate and an optical amplifier configured by selectively accessing the state-adjustable double-gain optical structures on the silicon substrate, the power of the laser is remarkably improved, a hybrid integrated chip structure is realized, optical fibers are not contained, and the laser has a wide application prospect. The laser is more compact and more stable in structure.

Description

Technical Field

[0001] The present invention relates to the technical field of lasers, and more particularly to a state-adjustable dual-gain optical structure on a silicon substrate and a laser. Background Art

[0002] Silicon-based optoelectronic integration technology has found widespread and significant applications in fields such as optical communications, optical interconnects, and optical sensing. However, the most significant bottleneck in this technology is the inability to directly generate laser light within silicon. Numerous solutions have been proposed to address this issue, with the most promising currently being the hybrid integration of III-V luminescent materials with silicon photonic chips to create silicon-based external-cavity lasers (ECLs). However, these lasers still face numerous challenges, such as achieving high-power lasers, wavelength-tunable lasers, and optical amplifiers.

[0003] In addition, in some optical systems that need to dynamically adjust the intensity distribution of optical signals according to actual working conditions, traditional external cavity lasers cannot easily adjust the ratio of transmitted light and reflected light, resulting in problems such as signal attenuation and interference during the transmission of optical signals, making it difficult to meet the needs of high-speed and stable data transmission. In the field of lasers, some applications require precise control of the reflection and transmission ratio of lasers to improve sensitivity and accuracy, but the limitations of existing laser structures make it difficult to achieve ideal performance in complex environments. Most existing tunable lasers achieve wavelength or light intensity adjustment through mechanical tuning, temperature tuning, etc., but these adjustment methods have problems such as slow response speed, low adjustment accuracy, and complex structure, and cannot meet the requirements of modern optoelectronic technology for high performance and flexible adjustment of lasers.

[0004] Therefore, a laser structure that can flexibly adjust laser power has become a technical problem that needs to be urgently solved in the current optoelectronics field. Summary of the Invention

[0005] In response to the problems in the background technology, the present invention provides a state-adjustable dual-gain optical structure and a laser on a silicon substrate to solve the defects of the laser in the prior art.

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

[0007] A state-adjustable dual-gain optical structure on a silicon substrate, characterized by comprising:

[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 connected to the first end and the second end of the first optical coupler respectively, the third end and the fourth end of the first optical coupler are connected to the first end of the third phase modulator and the first end of the fourth phase modulator respectively, the second end of the third phase modulator and the second end of the fourth phase modulator are connected to the first end and the second end of the second optical coupler respectively, the third end and the fourth end of the second optical coupler are connected to the first port and the second port respectively, the incident light enters from the first port, the reflected light is output from the first port, and the second port is used to output the transmitted light;

[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 reflective 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 and the reflected light electric field E Re and the transmitted light electric field E Tr The relationship between them is as follows:

[0012]

[0013] Among them, E In is the incident light electric field, r A is the amplification factor of the first reflective semiconductor optical amplifier, i is an 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 between the two reflective semiconductor optical amplifiers is adjusted. When the ratio of the reflected optical field to the incident optical 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 optical field to the incident optical field is greater than 0 and less than 1, the optical structure is configured as a semi-transmitter and semi-reflector.

[0015] A laser comprises: a semi-transmissive reflector and a first reflecting device, wherein the first port of the semi-transmissive reflector is connected to the first reflecting device; wherein the first reflecting device is a total reflector, a wavelength tunable reflector or a semi-reflector.

[0016] Preferably, a second reflecting device is also included, the second port of the semi-transmissive and semi-reflective 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 semi-reflector.

[0017] A laser comprises: two semi-transmissive reflectors, wherein the first port of one of the semi-transmissive reflectors is connected to the first port of the other semi-transmissive reflector, and the incident light of one of the semi-transmissive reflectors is reflected by two reflective semiconductor optical amplifiers inside the semi-transmissive reflector and then enters the other semi-transmissive reflector as incident light.

[0018] Preferably, an optical amplifier is further included, wherein the first port of the optical amplifier is connected to the first port of one of the semitransparent reflectors, and the second port of the optical amplifier is connected to the first port of the other semitransparent reflector.

[0019] Preferably, a tunable filter is further included, wherein a first end of the tunable filter is connected to the first port of one of the semitransparent and semireflective devices, and a second end of the tunable filter is connected to the first port of the other semitransparent and semireflective device.

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

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

[0022] (1) By utilizing the interaction between two reflective semiconductor optical amplifiers and cooperating with a first phase modulator and a second phase modulator directly connected thereto, a unique optical structure can be constructed to precisely adjust the phase relationship between the two.

[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 achieve effective amplification and output of the optical signal; when the ratio is between greater than 0 and less than 1, the optical structure is configured as a semi-transmitter and semi-reflector, which facilitates structural expansion and broadens the scope of application.

[0024] (3) Calculating the reflected light electric field and the transmitted light electric field based on the phase and gain ratio between the two reflective semiconductor optical amplifiers, the 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, thereby achieving flexible adjustment of the ratio of the transmitted light to the reflected light;

[0025] (4) Using a semi-transmissive and semi-reflective device configured with a state-adjustable dual-gain optical structure on a silicon substrate and combining it with a reflector to form a laser, the laser cavity Q value can be adjusted, and the laser power at each end face can also be adjusted;

[0026] (5) A laser is constructed by using a semi-transmitter and a semi-reflector configured with multiple state-adjustable dual-gain optical structures on a silicon substrate, and an optical amplifier configured with selective access to the state-adjustable dual-gain optical structure on a silicon substrate. The laser power is significantly improved. The hybrid integrated chip structure does not contain optical fibers, and the laser structure is more compact and stable. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0030] Figure 3 1 is a schematic structural diagram of a laser provided by an embodiment of the present invention;

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

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

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

[0034] Figure 7 1 is another structural schematic diagram of a laser provided by another embodiment of the present invention.

[0035] Reference numerals:

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

[0037] The following describes the embodiments of the present invention with reference to the accompanying drawings so that those skilled in the art can better understand the present invention and implement it. However, the enumerated embodiments do not limit the present invention. In the absence of conflict, the following embodiments and technical features of the embodiments may be combined with each other, wherein the same components are represented by the same reference numerals. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0038] The present invention proposes a state-adjustable dual-gain optical structure on a silicon substrate. Figure 1 , Figure 1 It is a structural schematic diagram of a state-adjustable dual-gain optical structure on a silicon substrate provided by an embodiment of the present invention.

[0039] See also Figure 1 In an embodiment of the present invention, the on-chip state-adjustable dual-gain optical structure 100 includes a reflective semiconductor optical amplifier pair 110 consisting 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 connected to the first ends of the first phase modulator 121a and the second phase modulator 121b, respectively, and the second end of the first phase modulator 121a is connected to the second end of the second phase modulator 121b. The first end and the second end of the first optical coupler 123a 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, the reflected light Re is output from the first port, and the second port is used to output the transmitted light Tr.

[0040] After entering from the first port, the incident light In is first split by the second optical coupler 123b, then phase-modulated by the third phase modulator 122a and the fourth phase modulator 122b, and then combined by the first optical coupler 123a. Finally, it passes through the first phase modulator 121a and the second phase modulator 121b and enters the reflective semiconductor optical amplifier pair 110 consisting of two reflective semiconductor optical amplifiers. The ends of the two reflective semiconductor optical amplifiers away from the first phase modulator 121a and the second phase modulator 121b are both coated with a highly reflective film. The reflected light is then phase-modulated by the first phase modulator 121a and the second phase modulator 121b, and then by the first optical coupler 123a, the third phase modulator 122a, and the fourth phase modulator 122b. Finally, it passes through the second optical coupler 123b to output the reflected light Re and the transmitted light Tr.

[0041] Figure 2 This is a schematic diagram of phase adjustment of a state-adjustable dual-gain optical structure on a silicon substrate provided by an embodiment of the present invention, see Figure 2 , there is a phase difference between the two reflective semiconductor optical amplifiers The first phase modulator 121a and the second phase modulator 121b are directly connected to each other to construct a unique optical structure, which can accurately adjust the phase relationship between the two reflective semiconductor optical amplifiers; the reflected light electric field E Re and the transmitted light electric field E Tr The relationship between them is as follows:

[0042]

[0043]

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

[0045] Thus, by adjusting the phase difference between the two reflective semiconductor optical amplifiers, the distribution ratio between reflected and transmitted light can be adjusted. When the ratio of the reflected optical field to the incident optical field is 0, no reflected light is output from the first port. At this time, only transmission occurs without reflection, which is equivalent to an optical amplifier. The corresponding optical structure is configured as an optical amplifier, denoted as 100-A. When the ratio of the reflected optical field to the incident optical field is greater than 0 and less than 1, the optical structure is configured as a semi-transmitter and semi-reflector, denoted as 100-R.

[0046] It is worth noting that the gain ratio between the two reflective semiconductor optical amplifiers, the 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 fixed values. Based on the phase difference between the two reflective semiconductor optical amplifiers, the reflected optical field and the transmitted optical field are calculated, and the ratio of transmitted light to reflected light can be flexibly adjusted. The ratio of reflected light to transmitted light can also be adjusted based on the phase and gain ratio between the two reflective semiconductor optical amplifiers, the 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, and the ratio of transmitted light to reflected light can be flexibly adjusted. 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 achieve effective amplification and output of the optical signal; when the ratio is between greater than 0 and less than 1, the optical structure is configured as a semi-transmitter and semi-reflector, which facilitates structural expansion and broadens the scope of application.

[0047] Figure 3 This is a schematic diagram of the structure of the laser provided by the embodiment of the present invention, see Figure 3 The laser includes: a semi-transmissive reflector 100-R and a first reflective device 210, wherein the first port of the semi-transmissive reflector 100-R is connected to the first reflective device 210; wherein the first reflective device is a total reflector or a wavelength tunable reflector or a semi-reflector.

[0048] Incident light is input to the first port of the transflector 100-R. After entering the optical structure and being reflected by two reflective semiconductor optical amplifiers, the incident light is output as reflected light at the first port and as transmitted light at the second port. The output reflected light can then be reflected by the first reflector 210 and return to the transflector 100-R as incident light. Multiple reflections form the laser's resonant cavity. The first reflector 210 can be a total reflector, a wavelength-tunable reflector, or a semi-reflector, all of which can reflect the output reflected light back to the transflector.

[0049] The present invention utilizes a semi-transmissive, semi-reflective device configured with a state-adjustable dual-gain optical structure on a silicon substrate, combined with a first reflector to form a laser. This allows for adjustable intracavity Q and adjustable laser power at each end facet. This not only increases laser power but also allows for adjustable output optical power.

[0050] Figure 4 is another structural diagram of a laser provided by another embodiment of the present invention, see Figure 4, also includes a second reflective device 220, the second port of the semi-transmissive reflector 100-R is connected to one end of the second reflective device 210; wherein the second reflective device 220 is a wavelength tunable reflector or a semi-reflector, and the other end of the second reflective device 220 is the output port of the laser; wherein the second reflective device 220 is a wavelength tunable reflector or a semi-reflector.

[0051] Figure 5 is another structural diagram of a laser provided by another embodiment of the present invention, see Figure 5 The laser includes two semi-transparent reflectors 100-R. The first port of the first semi-transparent reflector is connected to the first port of the second semi-transparent reflector. The incident light of the first semi-transparent reflector is reflected by two reflective semiconductor optical amplifiers inside the first semi-transparent reflector and then enters the second semi-transparent reflector as the incident light. That is, the reflected light of the first semi-transparent reflector serves as the incident light of the second semi-transparent reflector, and the reflected light of the second semi-transparent reflector serves as the incident light of the first semi-transparent reflector. After multiple reflections, the light forms a resonant cavity. The Q value of the laser cavity is adjustable, and the laser power at each end face is also adjustable. At the same time, a laser structure includes four reflective semiconductor optical amplifiers, and the laser power is increased by 4 times. This not only achieves an increase in laser power, but also realizes adjustable output light power.

[0052] In another embodiment, see Figure 6 An optical amplifier 100-A is also connected between the two semi-transparent reflectors 100-R. The first port of the optical amplifier 100-A is connected to the first port of the first semi-transparent reflector, and the second port of the optical amplifier 100-A is connected to the first port of the second semi-transparent reflector. Multiple optical amplifiers 100-A can be added inside the laser to further amplify the laser power.

[0053] In another embodiment, see Figure 7 A tunable filter 500 is connected between the two transflectors 100-R. The first end of the tunable filter 500 is connected to the first port of the first transflector, and the second end of the tunable filter 500 is connected to the first port of the second transflector. The tunable filter can be a double microring structure, turning the laser into a tunable laser.

[0054] The present invention utilizes a transflector configured with multiple on-chip, state-adjustable dual-gain optical structures on a silicon substrate, and an optical amplifier selectively connected to the state-adjustable dual-gain optical structure on a silicon substrate, to construct a laser. This significantly increases the laser power. The hybrid integrated chip structure does not contain optical fibers, making the laser structure more compact and stable. The laser structure composed of multiple on-chip, state-adjustable dual-gain optical structures on a silicon substrate contains multiple reflective semiconductor optical amplifiers. The light from these multiple reflective semiconductor optical amplifiers is mutually coupled and coherent, not simply superimposed. The laser structure based on the hybrid integrated chip can be further expanded to form laser radars, laser gyroscopes, and other devices.

[0055] The various embodiments of the present invention are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. Reference can be made to the common and similar parts between the various embodiments. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple, and the relevant parts can be referred to the method description.

[0056] The embodiments described above are merely preferred embodiments of the present invention. The phrases "in one embodiment," "in another embodiment," "in yet another embodiment," or "in other embodiments" used in this specification may refer to one or more of the same or different embodiments of the present disclosure. Any common changes and substitutions made by those skilled in the art within the scope of the present invention are intended to be encompassed within the scope of protection of the present invention.

Claims

1. A state-adjustable dual-gain optical structure on a silicon substrate, characterized in that: include: 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 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 connected to the first end and the second end of the first optical coupler respectively, the third end and the fourth end of the first optical coupler are connected to the first end of the third phase modulator and the first end of the fourth phase modulator respectively, the second end of the third phase modulator and the second end of the fourth phase modulator are connected to the first end and the second end of the second optical coupler respectively, the third end and the fourth end of the second optical coupler are connected to the first port and the second port respectively, the incident light enters from the first port, the reflected light is output from the first port, and the second port is used to output the transmitted light; 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 reflective 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.

2. The on-chip state-adjustable dual-gain optical structure according to claim 1, characterized in that: The phase difference between the two reflective semiconductor optical amplifiers and the reflected light electric field E Re and the transmitted light electric field E Tr The relationship between them is as follows: Among them, E In is the incident light electric field, r A is the amplification factor of the first reflective semiconductor optical amplifier, i is an 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.

3. The on-chip state-adjustable dual-gain optical structure according to claim 2, characterized in that: Adjust the phase between the two reflective semiconductor optical amplifiers. When the ratio of the reflected optical field to the incident optical 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 optical field to the incident optical field is greater than 0 and less than 1, the optical structure is configured as a semi-transmitter and semi-reflector.

4. A laser, characterized in that: include: A transflector as claimed in claim 3, and a first reflective device, wherein the first port of the transflector is connected to the first reflective device; wherein the first reflective device is a total reflector, a wavelength tunable reflector or a half reflector.

5. The laser according to claim 4, characterized in that It also includes a second reflecting device, the second port of the semi-transmissive and semi-reflective 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 semi-reflector.

6. A laser, characterized in that: include: Two transflectors as claimed in claim 3, wherein the first port of one of the transflectors is connected to the first port of the other transflector, and the incident light of one of the transflectors is reflected by the two reflective semiconductor optical amplifiers inside the transflector and then enters the other transflector as incident light.

7. The laser according to claim 6, characterized in that The optical amplifier further comprises an optical amplifier as claimed in claim 3, wherein the first port of the optical amplifier is connected to the first port of one of the transflectors, and the second port of the optical amplifier is connected to the first port of the other transflector.

8. The laser according to claim 6, characterized in that It also includes a tunable filter, wherein a first end of the tunable filter is connected to the first port of one of the semitransparent and semireflective devices, and a second end of the tunable filter is connected to the first port of the other semitransparent and semireflective device.

9. The laser according to claim 8, characterized in that The tunable filter is a double micro-ring structure, and the laser is configured as a tunable laser.

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