This PDF file contains the front matter associated with SPIE Proceedings Volume 11184, including the Title Page, Copyright information, Table of Contents, Author and Conference Committee lists

In this paper, a 6-channel wavelength-mode division hybrid multiplexer/demultiplexer based on photonic crystals is proposed. The device consists of three combined resonators, three wavelength selective reflection microcavities, single mode waveguides, multimode waveguides and tapered coupled waveguides. The filtering is realized by the structure of combined resonator and wavelength selective reflection microcavity, and the mode conversion is realized by the structure of the asymmetric parallel waveguide. The simulation analysis by time-domain finite difference method shows that the device can realize the multiplexing/demultiplexing of six channels, i. e. , the 1550 nm TE₀ mode, 1530 nm TE₀ mode, 1550 nm TE₁ mode, 1530 nm TE₁ mode, 1550 nm TE₂ mode and 1530 nm TE₂ mode. Its insertion loss is <0.132dB and the channel crosstalk is <-15.01dB. The device has important application value for large-capacity optical communication system.

The C- and L-bands (1530 nm ~ 1625 nm) are used for long-haul optical communication systems. The operating wavelength range needs to be extended to realize much broader transmission capacity with a low-cost modulation format. In this paper, we propose a large-scale wavelength multiplexer/demultiplexer using a conventional spatial grating in combination with arrayed-waveguide gratings (AWGs) to cover the whole fiber transmission wavelength range. The diffracted light from the spatial grating is spectrally decomposed and coupled to several AWGs for further demultiplexing. In this study, we designed a multi/demultiplexer which covers the O~L-bands (186.2 THz ~ 243.7 THz) with a channel spacing of 100 GHz. This has 9 sub-bands and 576 wavelength channels. The groove density of the spatial grating and the beam diameter on it are assumed to be 300 lines/mm and 1 mm x 1 mm, respectively. The diffracted light is coupled to 9 tapered waveguides on the edge of a planar lightwave circuit (PLC). The shape of the beam is changed by a cylindrical lens, to enhance the coupling efficiency. Each tapered waveguide is connected to an AWG with a center wavelength corresponding to the particular sub-band. AWGs with 64 output channels have a frequency spacing of 100 GHz. The transmission loss in the AWGs was calculated to be between -14.9 dB and -6.6 dB. The relatively large transmission loss was due to misalignment between the beam and the tapered waveguides.

We compare two silicon-based broadband 3dB directional couplers (DCs) with different structures and assess their fabrication tolerance and temperature tolerance. One broadband DC comprises 3-segment waveguides, with a device footprint 32μm×1.3μm, the other comprises curved waveguides, with a device footprint 20μm×3μm. By adding phase control waveguide region or modifying the effective refractive index of curved waveguides, the wavelength sensitivity of the two DCs is reduced. Simulation results show that both DCs achieve an operation bandwidth of over 80 nm (covering the whole C-band), compared to ~10nm for a conventional DC, the operation bandwidth is enhanced almost 8~10 times, which is highly desired in optical communications. For the further study, we assess the fabrication tolerance and temperature tolerance of two broadband DCs, simulation results show that both two DCs show good temperature tolerance, and the curved waveguide DC has better fabrication tolerance than 3-segment DC for synchronous variation.

Photonic switches based on phase change materials that are nonvolatile in nature and consume lesser power during switching process while having ultra-low footprint are emerging fast to address the challenges faced by modern interconnects. In addition to optical interconnects and optical communication at 1.55 μm wavelength, such devices are likely to be in great demand for emerging optical communication window around 2 μm wavelength. The switching in phase change materials can be triggered by electrical, optical or thermal means. One such material Ge₂Sb₂Te₅ is technologically mature, cost effective and compatible with CMOS fabrication technology. It can exist in amorphous as well as crystalline phase and remains stable in both the phases. It can be switched rapidly and repeatedly for realizing photonic switching devices around wavelengths 1.55 μm and 2.0 μm. By integrating Ge₂Sb₂Te₅ on silicon-on-insulator platform, the switching functionalities with high performance can be achieved. Here, we present various types of switches based on different hybrid Ge₂Sb₂Te₅-Silicon waveguide. Different geometries will be discussed for operational wavelengths of 1.55 μm and 2.0 μm. Different design strategies that lead to realization of high performance photonic switches in terms of extinction ratio, insertion loss, switching energy and re-configurability using ultra-compact Ge₂Sb₂Te₅ embedded within the silicon waveguide and having indium tin oxide electrodes are described in detail.

We propose a hybrid wavelength selective switch (WSS) using silica and silicon waveguides and describe its design. In the proposed design, silica arrayed waveguide gratings (AWGs) are connected to a silicon photonics switch array by free space optics. The wavelength multiplexed (WDM) signal input to the silica waveguide is coupled to a polarization beam splitter for polarization diversity, and one of the output signals is rotated by a half-wave plate so that both output signals had the same polarization. Each output signal is guided to an AWG and spectrally decomposed onto grating couplers in the silicon photonics chip. The two AWGs are identical and cover the whole C-band. The free space optics has cylindrical lenses to adjust the size of the light profiles to match the size of the grating couplers. The grating couplers are aligned seamlessly to realize a flexible-grid WSS. The optical signals from the grating couplers are guided to a 1 × N Mach-Zehnder interferometer (MZI) switch, and to N output grating couplers. In this design, N was set to 2, limited by the size of the silicon photonics chip. The optical signals emitted from the output grating couplers are again coupled to the corresponding AWG. Finally, the two polarized light signals are combined and output from the silica waveguide.

Hybrid plasmonic waveguides (HPWs) have become a hot topic in nanophotonic due to their excellent optical field constraints and low propagation loss. Based on the polarization dependence of surface plasmon polariton (SPP) excitation the symmetry of cylindrical vector beams, a cylindrical hybrid plasmonic waveguide (CHPW) realizing limited propagation and two tapered hybrid plasmonic waveguides (THPWs) achieving nanofocusing are presented. CHPW supports radial polarization mode and well compensate mode propagation loss by adjusting the structural parameters of the waveguide. Splendid mode limitation and long transmission distance with low loss can be achieved simultaneously. On the basis of CHPW, the structure is tapered to realize nanofocusing. And periodic grooves are constructed on the metallic surface of the tapered hybrid plasmonic waveguide (THPW) to meet the phase matching condition and maximize the coupling of light energy from inside to outside. Meanwhile, the low index layer of THPW is replaced with two different index layers, which is broadened to gather more energy efficiently and the energy is converged on the apex of the waveguide to form the ultrahigh field enhancement, which is another optional way to improve the performance of THPW. The results offer vital reference value for designing and manufacture related photonic devices.

Dispersion engineering in integrated waveguides and microresonators has been intensely studied in recent years. The main focus is to achieve desirable adjustment of dispersion value, slope, bandwidth and flatness, which is important for broadband nonlinear applications. Dispersion has been viewed as a control knob to leverage the parameter space provided by high-index-contrast on-chip devices, enabling strong interactions of far apart frequency components over an octavespanning bandwidth. Here, we review recent advances in dispersion engineering in integrated waveguides and microresonators based on various material platforms, with an emphasis on their applications in mid-infrared (IR) photonics.

A graphene photodetector based on ultra-thin silicon waveguide at 1.55μm is proposed. By reducing the silicon core thickness, the fundamental TE waveguide mode is less confined and light-graphene interaction is enhanced. Benefiting from the ultrathin silicon waveguide and reflector structure, the graphene absorption coefficient reaches 0.36 dB/μm. A 10nm-thick CVD-grown hexagonal boron nitride is covered on the graphene to improve the device performance. With the help of metal-graphene-metal structure, the contact resistance is reduced dramatically. The devices have shown a responsivity of 1.4 mA/W at 0 V bias and 23.1 mA/W at 0.3 V bias with 0.24 mW input optical power. The measured 3-dB bandwidth is 17GHz under 0V bias voltage at 1550 nm.

Optical injection in the semiconductor laser has been widely investigated in digital optical signal processing and microwave photonics. Red-shift is a typical nonlinear physical phenomenon in semiconductor lasers due to external beam injection. In this paper, we analyze the physical principle of the red-shift when an external beam is injected into a single mode Fabry-Perot laser diode (SMFP-LD). In our scheme, we observe the range of the red-shift in an SMFP-LD with respect to the change in power of the injected beam by measuring the variation of the RF signal generated by optical beating the injected beam and the corresponding longitudinal mode of the SMFP-LD. We measure the red-shift due to the power variation of the injected beam with both positive and negative wavelength detuning. At first, the wavelength detuning is made constant and later on, the wavelength detuning is varied to find the behavior of red-shift due to different wavelength detuning. In addition, the dependence of red-shift on the mode of the SMFP-LD, where the external beam is injected, is also analyzed. The variation in the red-shift due to change in the power of the injected beam is used to generate microwave signal with different frequencies at the output. Based on the output results of the variation of the red-shift and the output microwave signal, whether it is a linear or non-linear curve, the analysis can be utilized on different applications in the microwave photonics that includes 5G communication, radar applications, military communication, and many others.

We propose an AlInGaAs MQWs photonics integration device with directional coupler for multifunction of light emission/detection in infrared range, and realize the device on an InP based wafer. Two identical AlInGaAs MQWdiodes, working as light emission/detection device independently, are fabricated by two-step etching process on one wafer and connected by a directional coupler. The photonic integration device is prepared by two dry etching for III-V materials and electron beam evaporation for metal electrode. The MQW-diode for emission loaded with positive bias voltage operates in transmit mode, and emits light in infrared range. The MQW-diode for detection loaded with negative bias voltage operates in receive mode, and absorbs infrared photons transmitted by directional coupler connecting the two MQW-diodes. The absorbed infrared photons leads to a change in internal electric voltage across the p-n junction of the MQW-diode for detection. The opto-electrical characterization including current–voltage and electroluminescence spectrum are conducted. The coupling performance between the two MQW-diodes is also experimentally characterized by analyzing the induced photocurrent of MQW-diode for detection. We perform finite element simulation by beam propagation method (BPM) to evaluate the light coupling performance for the directional coupler. An on-chip communication test is also conducted to demonstrate the potential application of photonics integration device for transmission optical signal in infrared range.

We present room-temperature continuous-wave lasing of 1.31 μm multi-quantum well lasers on a novel defect-free heterogeneous III-V-on-silicon integration platform. The epitaxially grown laser structure on the platform shows significantly low dislocation density of 9.5×10⁴ cm^-2, leading to a minimal threshold current density of 813 A/cm². These results bring promise to create multi functionalities like source, modulation and detection, etc. on such a defect-free, low-cost, large-scale substrate for Datacom applications.

Graphene is a hot material for photodetectors due to its high carrier mobility, superior electronic and optical properties. However, the low optical absorption (2.3%) of graphene results in a low photoresponsivity, which limits its wide application in photodetection field. Three-dimensional (3D) graphene with connection carbon nanomaterials is expected to possess better optical and electrical properties than single-layer graphene. In this paper, we studied an ultra-broadband photodetector based on 3D graphene and investigated the different photoresponse with three kinds of 3D graphene including the 3D reduced oxide graphene foam (rGOF), the 3D Nickel (Ni) skeleton graphene foam (GF) and the 3D removal of nickel graphene foam (RNi GF). Obvious photocurrents and ultra-broadband absorption from ultraviolet (UV) spectrum to terahertz (THz) region can be measure in the three 3D GF. A high photoresponsivity of 50 mA W^-1 and a fast time response of 100 ms have been achieved. Particularly, the 3D RNi GF presents the highest absorption coefficient of 200 cm^-1 at THz region. The results reveal 3D graphene a good candidate for broadband photodetectors.

The search for new doping material in S and near-C band communication window could prove as a boon for data traffic to which Thulium fits the slot optimally. The paper presents the performance estimation of Thulium doped fiber amplifiers (TDFAs) through ion-ion interaction mechanism (IM) effects consisting of homogeneous up-conversion (HUC) and pair induced quenching (PIQ) processes, also called clustering effect. Typically, the IM effects were studied as detrimental effect on signal gain, but in this work it was shown that they can also act as aiding mechanisms for early population inversion and lasing conditions at relatively lower pump power. Design parameters of TDFA were studied by carrying out the computational simulations on MatLab and OptiSystem 16 based on the mathematical model. The obtained results infers about the constructive nature of the IM effects. The optimum performance estimation parameters TDFA length was determined as 100 m with dopant area of 1μm. Due to the interplay of IM effect the optimum pump power was determined as 450 mW and signal gain of 20.32 dB instead of 650 mW when no IM effect was considered. The signal wavelength for minimum noise figure was calculated as 1460 nm. The work presented may be considered as a step closer to S and near-C band fiber optic communication systems.

With the rapid development of science and technology, virtual reality (VR) systems have developed rapidly. VR systems can be applied in many fields such as education, medical, military, and probing. According to the survey, the VR system will have a delay in the process of acquisition, transmission and processing, and more than 40% of the human body will have motion sickness after experiencing VR. The cause of motion sickness is delay. Accurate measurement of delays therefore helps to resolve motion sickness in the virtual world and provides guidance for the upgrade of these systems. In response to the existing problems, our research team designed a low-cost, high-performance experimental equipment that uses a single-chip microcomputer and a PIN photodiode as the hardware core of the delay detection device. The light intensity changes are used to determine the start and end of the detection. The algorithm calculates the delay time of the VR device.

We propose and experimentally demonstrate an RF signal multiplier based on harmonics injection locking to a single mode Fabry-Pérot laser diode (SMFP-LD) followed by an optoelectronic oscillator (OEO). The injected beam is generated by a tunable laser, which is modulated with a frequency f_m generated by a microwave source. Then the modulated beam is optically injected to the SMFP-LD with a negative wavelength detuning ▵λ, where one of the harmonics of the injected beam is locked to the corresponding mode of the SMFP-LD. Hence, due to the power gain of the SMFP-LD to the optical harmonics of the injected beam, stable electric harmonics of the modulated frequency with high signal to noise ratio (SNR) are generated by beating the output of the SMFP-LD after optical injection. In order to obtain one of the generated electric harmonics signals, we employ an OEO feedback loop to optimize the signal with high purity, which is determined by the electrical bandpass filter (EBPF) and the low noise amplifier (LNF) in the OEO loop. As the gain of the OEO loop is higher than the loss, a high-purity oscillating signal can be generated. In the experiment, we generate a sextuple signal (20 GHz) of the modulated frequency with the SNR and phase noise of 51.14 dB and -102.44 dBc/Hz@10kHz, respectively. Compared with other photonics structure to generate multiple frequency, the proposed method shows a simple structure, high SNR, easy to operate and low phase noise.

Depositing a high secondary electron yield (SEY) film on the microchannel plate (MCP) input electrode is supposed to be an effective approach to improve the photoelectron collection efficiency (CE) of photomultiplier tubes based on MCPs (MCP-PMTs). Nevertheless, secondaries promoted by the photoelectrons striking the MCP input face may cause a long tail in the time distribution of the output electrons (TDOE). In our work, laying a conductive grid upon the MCPs is proposed as an effective approach to suppress the tail. A three-dimensional MCP-PMT model is developed in CST STUDIO SUITE to systematically investigate the dependence of the TDOE on the applied voltage (U) of the grid at the coated material SEY=6. Simulation results show that high voltage applied on the grid could suppress the delay pulse effectively. The optimal U is above 500 V.

This work reports a graphene cylindrical hybrid plasmonic waveguide (GCHPW) consisting of a high-index dielectric core, a sandwiched low-index dielectric layer and a single layer graphene. Unlike traditional metallic cylindrical hybrid plasmonic waveguide (CHPW), GCHPW’s advance is that the nano-thickness light field can be significantly enhanced in the sandwiched low-index dielectric layer and the graphene interface, and a superior performance is achieved. Furthermore, the electromagnetic parameters of graphene is tunable, and the mode properties of the waveguide depend on the structural parameters, so the mode area and transmission distance can be flexibly optimized by adjusting these parameters. TM₀₁ mode with radially polarized transverse component is supported in the novel GCHPW, and a more compact confinement of light field is achieved. Additionally, the GCHPW has a smaller size compared with the CHPW. This study provides a valuable reference for design of graphene plasmonic waveguides and offers a new way for the limited transmission of radially polarized light.

The GaN/AlN QDs with different height and density are grown by MOCVD in Stranski-Krastanov (S-K) method. The growing of self-assembly GaN quantum dots (QDs) in S-K method is attributed to six key growth parameters of Ⅴ/Ⅲ ratio, growth interruption, growth duration, flow rate, growing temperature and the NH₃ protective atmosphere during cooling down. The surface free energy and GaN deposition amount on the growth front are modulated by adjusting the 6 conditions in epitaxial process of GaN QDs. The influence of the six growth factors on GaN QDs and the mechanism of which are systematically analyzed, the appropriate growth windows of each factor are obtained by optimizing experiments. The uncapped GaN QDs possess excellent photoluminescence performance.

This paper introduces radial multi-sub-mirror (MSM) synthetic aperture system structure and imaging characteristics of the liquid lens based, and the MSM array for the simulate imaging and image restoration. In order to obtain the scaling invariance of MSM system imaging, the dimensionless method is used to reduce the structural parameters. Baseline statistical distribution diagram and modulation transfer function (MTF) are used to analyze the structural characteristics and intermediate frequency(IF) characteristics. The MSM optical characteristics are calculated and the raw image is simulated under different filling factors. For the reduction of the IF characteristics of the synthetic aperture system, the raw image is restored by Wiener filtering. Using the standard deviation and peak signal-to-noise ratio between the synthetic aperture imaging system and the filled aperture imaging system, these two indicators evaluate the image quality with different fill factors. A comparative analysis of the restored images yields a relationship between filling factor and image quality. Since the large number of sub-mirrors in the MSM array, resulting in a larger number of different baselines. Because the baseline corresponds to the distribution characteristics of spatial frequency, the baseline of the MSM has a large number of repeats in the IF region, so the structure has a good response of IF. The results showed that as the sub-aperture diameter increases, the imaging quality of the MSM structure becomes better. The image restoration effect enhance with the increase of the filling factor. After wiener filtering, the image quality is improved.

The work presents for the first time generation of complex optical waveforms in a hybrid mode-locked fibre-semiconductor laser. We experimentally show that with mode locking by synchronous pumping of the semiconductor active medium, almost arbitrary temporal pulse profiles are possible by appropriate shaping of the electric pumping pulses. Discussed are limitations and possibilities of electro-optical pulse shape transfer in mode-locked lasers on a nano- and micro-second duration scales and the prospect of shorter time scales. Demonstrated generation of stable periodic optical waveforms with specified structure opens up the potential of new laser sources with widely controllable pulse shape for research and practical applications.

Epitaxial growth of a high-quality InSb layer on a mismatched substrate which provides a path to monolithically integrate InSb-based photonic devices and Si/GaAs-based electronic devices on a single wafer. This work is an attempt to investigate the effects of In_0.9Al_0.1Sb electron barrier layers on the electrical and optical properties of the InSb photodetectors on a mismatched substrate. The structure of InSb photodetector is p-i-n type where i-layer is the unintentionally n-type doped. A 25 nm In_0.9Al_0.1Sb layer locates in the i-layer. At 77 K, InAlSb barrier can effectively decrease dark current due to it completely suppresses the generation and recombination current and tunneling current and partially suppresses the diffusion current. The different dark current mechanisms (diffusion, generation and recombination, tunneling) are discussed associated with the bandgap diagrams. For the simulation of photoresponse, the incident light is set to be 5.3 μm. At 77 K, the existence of InAlSb layer doesn’t influence the absorption of incident light due to its limited thickness, however, the InAlSb layer separates the i-layer and impedes the transportation of electrons. Therefore, the InAlSb layer decrease the photoresponse of InSb detector and its effects is more remarkable when the diffusion length of hole is around 5 μm or its location is near the surface of the detector. According to the simulation, optimizing the location of the In_0.9Al_0.1Sb is important to increase the performance of InSb photodetectors on a mismatched substrate.

In this work, a bidirectional grating coupler for perfectly vertical coupling with enhanced coupling efficiency is proposed. A silicon nitride layer above the grating regain is utilized to enhance the coupling efficiency. With the help of the silicon nitride layer, reflection back into the fiber is diminished and maximal coupling into the guided mode is achieved. In addition, this grating coupler shows strong fiber misalignment tolerance. Genetic algorithm (GA) is used to simultaneously optimize the grating and silicon nitride layer. The optimal design obtained from GA shows that the total in-plane optical coupling in C-band is enhanced from about 56.3% to 67%; meanwhile the back-reflection is reduced from 17.6% to 5.3%. What’s more, the device proposed here shows a wide-band character with a 1-dB-bandwidth of 54 nm. Such a design can provide an efficient and cost-effective solution for optical vertical coupling of a WDM application and low-cost fiber packaging for silicon PIC.

This paper presents a 1×4 polarization-independent beam splitter based on silicon waveguides. The device is mainly consisted of a coupling structure and a sub-wavelength structure. According to the coupled mode theory, in the traditional directional coupled structure, the coupling strength of TM mode is stronger than that of TE mode, which makes it difficult to realize polarization-independent beam splitting. Adding a sub-wavelength structure in the coupling region can weaken the coupling strength of the TM mode while enhancing the coupling strength of the TE mode, so that the coupling strengths of the TE mode and the TM mode are equal. Therefore, polarization-independent beam splitting can be achieved by adjusting the parameters of the directional coupling structure and the sub-wavelength structure. The time-domain finite difference method (FDTD) is used for simulation analysis. The simulation results show that the device can realize polarization-independent beam splitting at 1550nm, the insertion losses of TE and TM modes are 0.36 dB and 0.55 dB, respectively. The length of the device is 23.421 μm and the bandwidth is about 10 nm. The device has the advantages of small size and simple structure, and it is easily to be integrated.

We propose a novel way of radiation wavelength stabilisation in atomic clocks based on coherent population trapping (CPT). It uses quadrature-phase component of the CPT signal within the CPT resonance feedback loop and automatic wavelength locking of radiation from a VCSEL to the atomic absorption line. We demonstrate advantages and limitations of the new method applied to vapour cells with buffer gas or anti-relaxation coating. Also provided are measurements of short- and long-term stability of a CPT-based atomic clock using the proposed method with various optical cells. Discussed are the prospects of this method in chip-scale atomic clocks.

Laser induced breakdown spectroscopy (LIBS) is a type of atomic emission spectroscopy which uses a highly energetic laser pulse as the excitation source. The laser is focused to form a plasma, which atomizes and excites samples. The formation of the plasma only begins when the focused laser achieves a certain threshold for optical breakdown, which generally depends on the environment and the target material. Thereby, the detection and spectral analysis of the elements contained in the object are realized. However, the traditional LIBS system cannot achieve non-contact adjustment. When detecting objects underwater, the optical path is fixed and cannot be re-adjusted to accommodate the external environment. In this paper, the optical path system is integrated into the pressure cabin and controlled by a microcontroller unit. The host computer is connected to the microcontroller unit through the TCP/IP protocol. Then the focus of the optical path and the brightness of the illumination source can be adjusted by the PC through the host computer. An underwater HD camera is controlled by the host computer to realize in-situ detection and monitoring of the elements contained in the underwater object. Compared with the traditional LIBS system, the advantage of this system is that the underwater non-contact optical system can be adjusted and focused by the host computer. At the same time, the underwater object can be monitored by the high-definition camera to realize the in-situ detection and monitoring of the elements contained in the underwater object, so as to achieve accurate underwater positioning.

Quantum dots have widely used in a lot of micro-nano photoelectric devices. In this work, PbS quantum dots have been synthesized successfully then a RRAM based on those quantum dots and PMMA mixture material was prepared by solution processed method at room temperature. We have demonstrated that the memory device shows typical resistance switching characteristic and high resistance ratio ( >10⁴). To study the quantum dots based RRAM provides an opportunity to develop the next generation high-performance memory devices and open up a new application field of QDs materials in the future.

Wide bandgap compound ZnS is one of the promising materials used in versatile applications including solar cells, UV photodetectors and luminescent devices. Compared to other II-VI sulfides, ZnS has several advantages of non-toxicity, wider solar spectrum transparency and earth-abundance. Recent progress on optimization of synthesis techniques of ZnS allows it to be effectively realized on transparent and flexible substrates. In this work, nanostructured ZnS films were deposited on bare quartz and ITO coated glass substrates using RF sputtering at various conditions. Crystal structural, optical and surface chemical properties of ZnS films have been systematically characterized. It is revealed that ZnS films exhibit cubic β-phase crystalline structures on both substrates. The optical transmittance of ZnS films is above 85% in the visible range. The substrate temperature plays an important role in crystalline quality of ZnS films. Sputtering power exhibits more effects on the thickness and optical properties of ZnS films. Optimization of deposition parameters has been realized by investigation of optical, microstructure and crystallinity of ZnS thin films in this study.

We demonstrate microring lasers based on Si₃N₄ optical waveguides cladded with MAPbBr₃ quantum dots composite film. Si₃N₄ microrings are designed and fabricated with electron beam (E-beam) lithography and inductively-coupled plasma reactive-ion-etching followed by spin coating a MAPbBr₃ quantum dots composite film on them. We clearly observe the lasing modes with narrow linewidths for both TE- and TM-polarization modes when the microrings are optically pumped with a nanosecond laser. The experimental results show that the laser has a typical linewidth of 0.23 nm and a minimum pump power of 8.46 μJ/cm².