Session Index

Photonic-crystal surface-emitting laser which has advantages of high power, small divergence angle, circular light output, stable single-mode operation and beam tailoring capability. In order to meet the requirement of outdoor 3D sensing and light detection, further improving of the output power is a matter of consequence. We propose and demonstrate a new way to fabricate PCSEL arrays and analyze the influence of design parameters.

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We developed a four-stage integrated photonic circuit based on type-0 spontaneous parametric down-conversion (SPDC) and electro-optic (EO) techniques. The chip combines the functions of photon-pair generation, high efficiency polarization mode conversion (PMC), and phase modulation (PM). We systematically verify those functions above and demonstrate their high performance. The developed chip provides a compact and robust platform for generating and manipulating nonclassical light, which has huge potential for application to optical quantum computing and quantum communication.

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A novel electrode design in compact VCSEL array that effectively enhances high-speed data transmission has been demonstrated. Simultaneously, it exhibits dampened and wider 3-dB E-O bandwidth (18 vs. 14 and 11 vs 9 GHz), better eye-pattern quality and narrow divergence angle (FWHM: 11o and 9o).

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The passively mode-locked Er-doped fiber lasers (PML-EDFLs) was demonstrated by using graphene oxide/silk fibroin (GO/SF) films as a saturable absorbers. The modulation depth (ΔT) and saturation intensity (Isat) of GO/SF, around 3.63 % and 17.01 MW/cm2, respectively, has been obtained by means of nonlinear optical transmittance measurement. As pump power increases from 154 to 244 mW, the EDFL can be operated at fundamental mode-locked state without pulse splitting. The mode-locked pulses revealed the 824 fs pulse duration τ, 19.06 kHz repetition rate, and near transform limited TBP around 0.326.

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We designed and manufactured a low-cost, high-reliability 1.3 μm DFB for direct modulation applications. The carrier injection efficiency is improved by optimized epi-structure, which further enhances the high-speed characteristics of DFB lasers in high-temperature environments. The threshold current of the DFB laser is less than 10 mA at room temperature, the optical intensity exceeds 20 mW, and the SMSR is greater than 50 dBm. Under high-temperature conditions, the modulation frequency exceeds 17.1 GHz.

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This study investigates a high-entropy and broad-band chaos generation technique based on two mutually coupled semiconductor lasers for true physical random number generation. The proposed chaotic source can work as a 5-bit physical random bit generator at a rate of 50 Gbps with guaranteed unpredictability.

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We propose a novel all-optical photonic approach for high-frequency microwave generation based on period-one dynamics of two mutually coupled semiconductor lasers under highly asymmetric coupling strength. As a result, a 73.1-GHz microwave with a 3-dB linewidth below 3 kHz and a side-peak-suppression ratio above 45 dB is generated.

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We demonstrated the high-order vortex beam with the photonic-crystal surface-emitting lasers (PCSELs) in honeycomb lattice. The laser structure, photonic crystal band diagram, the light-current-voltage (L-I-V) curves and the far-field patterns were presented in this article. Furthermore, the result also contained the vortex analysis, and it showed that the PCSEL had high-order vortex beam with orbital angular momentum l=±2.

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Progress in understanding resonant subwavelength optical structures has fueled a worldwide explosion of interest in both fundamental processes and nanophotonic/plasmonic devices for imaging, sensing, solar energy conversion, and information processing. However, plasmonic platforms in the visible region with robust, high performance, thermo-stable, and low-cost remains remain unexplored. In this presentation, I will particularly discuss emerging plasmonic platforms based on transition metal nitrides. I will present an overview of my research works over the past five years on the plasmon-enhanced light-matter interactions in the visible regions and its applications [1-6], including the plasmonic nanolasers [1-2], tunable plasmonic modulators [3], plasmonic phototransistors [4], plasmon-enhanced solar energy harvesting [5], and the refractory plasmonic colors for back-light free displays [6]. My group discovered several unique working mechanisms that utilize plasmonic nanostructures to improve optoelectronic device performance. By engineering the local electromagnetic field confinement, the light-matter interaction strength can be enhanced, which results in efficient energy conversion in the designed nanosystem. The detailed mechanisms and possible applications will be discussed. These results have broad implications for the use of plasmonic crystals/metasurfaces in high-performance optoelectronic devices with efficient energy conversion.


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In recent years, high-speed data transmission has become an important issue for the needs of high-resolution image/audio, data streaming, and data cloud storage/computing. At the transmitted end, the VCSEL has been developed to enhance transmission capacity because of its great performance. With some tradeoffs, the few-mode (FM) VCSEL has emerged as a suitable solution for increasing transmission capacity and distance. In addition, after performing waveform pre-emphasis processing, the allowable NRZ-OOK data rate is increased to 69 Gbit/s. And for 69 Gbit/s NRZ-OOK transmission, the received BER of less than 2.6 × 10−5 is still lower than the forward-error correction criterion.

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In this manuscript, A 1270nm uncooled directly-modulated, InGaAlAs multiple quantum wells (MQWs) high speed DFB laser was demonstrated. A small signal frequency response bandwidth 20GHz was achieved at 45 °C. Furthermore, we realized 25Gb/s non-return-to-zero transmission with a clear eye-opening feature at room temperature (25 °C).

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We report the use of cascaded multi-plate supercontinuum that generate 12 fs, 515nm pulse with pulse energy 120 uJ and achieve pulse broadening for 6 fs transform limited.

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We report on the first observation of bound solitons in Cr-Er co-doped passively mode-locked fiber laser. The employed gain fiber is a Cr-Er co-doped mode-locked fiber, which enables broader emission spectrum than commercial Er-doped fibers and owns unique optical parameters allowing us to obtain the bound soliton operation easily. Both conventional and bound solitons can be generated in the same passively mode-locked fiber laser, and the operation states can be easily switched through the adjustment of pulse polarization.

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The pulse duration of the de-chirped pulses of around 1 m regime has been measured by the fringe-resolved autocorrelation (FRAC) through the nonlinear absorption of the ZnSe plate. Here, the de-chirped pulse was produced from the pulse amplifier of dissipative soliton from all normal dispersion passively mode-locked Yb-doped fiber laser (ANDi PML-YDFL) and compression by the grating pair. Through the measurement of de-chirped pulse around 1047nm, we demonstrated that the emission intensity of ZnSe reveals a quadratic increase with the pump intensity, which demonstrated the domination of the two-photon absorption (TPA).

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We have generated 0.2~0.3-MW peak power at 5.7 THz from a KTP difference-frequency generator. In my presentation, I will update the audience our most recent result toward generation of MW power from our unique source.

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We report a high-power LED-pumped Nd:YAG laser. When operating at a quasi-CW mode, the laser produced 450-mJ energy at 1064 nm in a 550-μs pulse width. When operating at a Q-switched mode, the laser produced 278-mJ energy in an 80-ns pulse width, which has a corresponding peak power of ~3.5 MW.

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We demonstrate a dual-wavelength Nd:YVO4 laser where either or both of its emission lines can be simultaneously selected and Q-switched electro-optically (EO) using an intracavity domain-engineered LiNbO3, designed based on aperiodic optical superlattice technique. EO spectral and Q-switching at dual 1064- and 1342-nm lines, single 1064-nm line, single 1342-nm line, and their second-harmonic and sum-frequency generation lines has been achieved with this novel laser system simply by voltage control.

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A mode-locked source operating at 1064 nm producing 14 ps bright pulses and synchronously generating dark pulses with similar width at 1342 nm, with a repetition rate of 276 MHz and output power of 102 mW is demonstrated. It is achieved by two Nd:YVO4 cavities operating at different wavelengths that interact in shared section through a PPRKTP crystal phase-matching for sum-frequency mixing.

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We introduce a new post-compression to achieve 50-fold compression of millijoule-level pulses at 1030 nm from 157 fs to 3.1 fs, with an output pulse energy of 0.98 mJ and an overall efficiency of 73%. When driving high-harmonic generation, these singlecycle pulses enable the creation of isolated ≈ 290-attosecond pulses.

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A new scheme of ion-based, phase-matched high-harmonic generation is proposed. It is inherently a single-attosecond-pulse x-ray source. The time-dependent phase-matching condition gates the output to be a single-attosecond pulse with a duration as short as 50 attoseconds. The scheme can be operated from water-window soft x-ray to 1.5-keV hard x-ray.

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In this study, we design the structure of the Vertical-Cavity Surface-Emitting Laser (VCSEL) tunnel junction to improve the insufficient output power and conversion efficiency for medium- and long-distance sensing by numerical simulation. Through analyzing the thickness, doping concentrations, and oxide layer of the tunnel junction to optimize the performance of the 940 nm tunnel junction VCSEL.

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We build a system to analyze single VCSEL’s thermal characteristics, and extend it to the
VCSEL array. We also verify the VCSEL’s performance under different short pulse conditions by
simulation and measurement. Throughout the study, we theoretically and experimentally show that the
VCSEL array’s performance is significantly affected by the thermal effect

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A tunable dual wavelength optically pumped semiconductor laser (OPSL) is demonstrated by using the birefringence plate (BRF). The wavelength spacing can be significantly varied by selecting proper material. Furthermore, the wavelength spacing can be slightly adjusted by changing the BRF thickness. Finally, the central wavelength can also be adjusted by controlling the temperature of the gain chip.

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A 3D printed PQ/PMMA was successfully made by Doping PQ within transparent resin. A PQ-resin dropping surface treatment makes VBG recording possible. 3D printed VBG has been successfully used as a laser mode control element. The fabrication time and preparation procedures have been greatly reduced.

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This work investigated the feasibility of using COF for mode-locked fiber lasers in the L band region. The mode-locked Er-doped fiber laser with 445fs pulse width,0.12 nJ pulse energy, and 14.72MHz repetition rates was demonstrated. In addition, the mechanism of mode-locking is also discussed.

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The research shows that Darlington LET's current gain and optical light output under VCE = 3 V and IB = 1 mA at ambient temperature enhances 125.76 % and 153.25 % more than single LET, respectively. In addition, the Darlington pair circuit will increase the current gain with a temperature (T) function. The current gain of Darlington LET improves 231.43 % from room temperature to 358K, which is desirable for the high-resolution thermal sensor.

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High-transverse-order pulsed fields with oval-shaped beam profiles are generated by an Nd:YVO4/Cr4+:YAG laser in a near-hemispherical resonator. Via the thermally-assisted variation of mode-matching conditions between the pump and cavity modes, the mode order of the generated oval structured fields can be straightforwardly controlled by the input pump power. At a pump level of 7.9 W, the average output power can reach up to 2.5 W with the pulse repetition rate and peak power respectively beyond 164 kHz and 709 W while maintaining stable temporal behavior for the output pulse trains.

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Nonlinear dynamics of the chaotic states generated by the optical feedback and polarized optical feedback are discussed in numerical simulations. In this paper, we focus on the study of chaotic states.The output light from polarized optical feedback system, efficiently reduced the effective bandwidth in chaotic states and narrowing the self-coherent of the peaks are studied and compared. Moreover, the detailed characteristics in different operational parameters are also considered.


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In this study, we used Ta2O5 thin film as the material of the optical waveguide core layer and successfully through the Ti׃Sapphire pulsed laser with a center wavelength of 800nm to generate Supercontinuum Generation (SCG) in the visible light band of high-order modes and discuss its possibilities and properties.

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High harmonic generation is driven by short-wavelength electromagnetic waves in laser-plasma interactions. Its conversion efficiency is determined by the relative phase between the driving laser field and the harmonic field, which is affected by various dispersive effects. Therefore, we mainly proposed to achieve the dispersion balance between intrinsic dipole phase variation, Geometrical phase shift, and plasma dispersion under strong ionization regime. The scheme will be verified by 3D particle-in-cell simulation (PIC) for the HHG order 203rd corresponding to the water window X-ray, i.e. 4 nm.

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High-order structured vector beams with transverse patterns as quasicrystal and superlattice are generated based on a Fourier optic system. By varying the arrangement of ring-distributed point sources on the near-field mask or tuning the principal orientation of vortex retarder to result in the radially-polarized state for the input beam, the polarization-dependent mode structures of the generated vector beams can be flexibly adjusted and well predicted by diffraction theory to offer promising light sources for potential applications.

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We demonstrate that a family of vortex-lattice structures can be flexibly generated using a multi-beam interference approach. Based on the numerical analysis, we experimentally realized these structure beams by combining an amplitude mask with multiple apertures and a spiral phase plate. The excellent agreement between the experimental and theoretical results not only validates the presented method, but also manifests the structure of vortex lattices. Moreover, the optical structure beams are exploiting to fabricate liquid crystal (LC) grating and periodic nanoarrays structures. We believe this approach is a powerful tool for fabricating periodic structures.

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Quantum target detection (QTD) utilizes nonclassical resources to improve the performance of radar target detection in a lossy and noisy environment. Here, we report a numerical analysis of optimal probe states (OPSs) in single-mode and one-shot QTD for the condition of arbitrary reflectivity of target. Our results show the OPS is non-Gaussian in most reflectivity except for a specific situation, due to the information source competing between the phase or photon number distribution. This theoretical model provides a concise tool for optimal detection and further toward optimal multi-mode QTD.

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Structured pulsed fields with high-order transverse structures as Lissajous curves have been generated by an Nd:YVO4/Cr4+:YAG laser. A concave-convex resonator was designed to achieve the strongly intracavity focusing on the absorber and the larger astigmatism for high-order mode operation at the same time for good passively Q-switched performance. Though the multimode operation leads to the parasitic effect, the overall temporal behavior of the pulse trains for the Lissajous pulsed fields has been manifested to present quite regular and stable. The overall peak power for the primary pulses can reach up to 300 W when pump power is 3.5 W.

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In this article, we put a batch of 850-nm vertical-cavity surface-emitting laser (VCSEL) chips in the high-temperature operating life (HTOL) tests and investigate their failure mechanisms. Light-current-voltage (LIV) characterization and near-field profiling are used to identify and analyze the damaged regions in the VCSELs.

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Passively Q-switched laser energy is theoretical analyzed and experimentally verified to achieved high pulse energy output. By using such laser source, the mid-infrared output is then converted and optimized by comparing four types of optical parametric oscillation structures.

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Through a 4-f system built by several high reflective concave and flat mirrors, the pump laser at 940nm can be absorbed by Made in Taiwan thin Yb:YAG crystal in multi-pass and then produce 1030nm cw laser with high slope efficiency to achieve high power. Also, by bonding thin disk Yb:YAG on a water-cooling module, heat can be cooled to let thermal problem like thermal lensing be controlled.

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Table-top hard X-ray sources have drawn significant attention recently. Betatron radiation, one of the X-ray sources, is expected to be an alternative to large synchrotron radiation facilities. In this study, the experimental condition of high brightness and polarized X-ray using the NCU 100 TW laser system is evaluated numerically. Simulations show that the shock-front injection electrons produce electrons with high peak energy and a low energy spread. By tilted shock front (TSF) [1,2], electrons injected from one side of the plasma wave significantly increase; their coherence is also enhanced. And, the electron beam is expected to generate polarized X-rays.

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The conversion efficiency of laser-produced plasma (LPP) extreme ultraviolet (EUV) is a crucial issue for the semiconductor industries (e.g. TSMC, ASML) which requires high power EUV light source. The one-dimensional simulation framework is developed that integrate the plasma simulation code MEDUSA with atomic model and radiative transport equation. The framework is based on multiple time scales and employs quasi-equilibrium assumption. We discover an empirical equation relating to the laser wavelength using a parametric study of the incident laser and propose a simple physical explanation.

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We present the study of the formation of conjugated resonator in the circular ring laser diode by the excitation of conjugated reflection due to enhanced optical nonlinearity of the quantum wells material and the strong laser emission in the circular ring resonator. The circular ring laser diode is consisted by a ridge waveguide circular ring resonator and a Y- junction coupler. Measurements of the mode spacing of the laser emission from the Y-junction output coupler and the soliton waveguide terminal were fit with the calculated length of the resonator.

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We model the cross-relaxation mechanism in a thulium Q-switched ytterbium-doped all-fiber fiber laser using a set of rate equations. The results reveal that a strong cross relaxation in a highly Tm-doped fiber is preferable for stabilizing Q-switching operation and preventing the system from deteriorating to CW lasing.

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A pulsed vortex laser formed by coherent superposition of off-axis resonating traveling waves was built in an azimuthal symmetry breaking laser cavity with an intra-cavity spiral phase element. Sub-ns pulse as a result of mode coupling of the longitudinal modes spectrally separating by one free spectral range was observed in addition to periodic and chaotic oscillation under passive Q-switched operation.

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Simultaneous multi-peak in orange-yellow band laser source was demonstrated by using intra-cavity second harmonic generation technique on periodically-poled-lithium-tantalate (PPLT). Our design showed the efficiency of the sum frequency generation of two idlers was comparable with second harmonic generation of each idler.

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We report fs laser direct writing waveguides in z-cut MgO-doped congruent lithium niobate crystal. The propagation loss in different processing parameters including laser pulse energy, and pattern distribution were studied. A 1064 nm DFB laser was adopted to characterize the guiding performances and the propagation loss was measured in the range of 2~6 dB/cm.

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High-order modes are generated by using a selectively off-axis pumped Nd:YVO4/KGW Raman lasers with intracavity second-harmonic generation (SHG) at 588 nm. Various structured lights are produced by converting the High-order modes through an astigmatic mode converter (AMC). The experimental results of the propagation for the High-order modes conversion are theoretically analyzed, and the phase structure is numerically calculated to confirm the robustness of the optical vortices.

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We investigated the polarization properties of scattering light from the KGd(WO4)2 crystal by the use of linearly polarized incident light. The polarization characteristics at Raman shifts of 768cm-1 and 901cm-1 vary with the angle between the incident light and the KGW crystal.

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Controlling emission properties of a quantum emitter (atom, fluorophore, quantum dot, etc.) through optical cavities is a central topic in cavity-QED. Here, our fabrication process provides a stable platform consisting of fluorophores and a plasmonic nanocavity. The emission property of this system is complicated. Polariton emission, resonant Raman scattering, surface-enhanced fluorescence can be observed depending on the coupling strength and the excitation wavelength.

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In this study, thermal characteristics of high power 940nm flip-chip vertical cavity surface emitting laser (VCSEL) array with different heat sink is investigated. According to the measurement results of wavelength to temperature dependence of the flip-chip VCSEL array, copper heat sink with an additional diamond-like carbon (DLC) coating can help to promote heat dissipation of VCSEL array during operation and obtain better wavelength to temperature stability than using conventional copper heat sink. The wavelength to temperature dependence can be as low as Δλ/ΔT=0.0486 nm/K.

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In this paper, nonlinear dynamics of the period-one dynamic generated by the optical feedback and polarized optical feedback are discussed in numerical simulations. The period-one dynamic obtained by polarization rotated feedback system show better performances by compared with those generated by traditional optical feedback system when the polarization angles and bias currents are properly adjusted. Moreover, the detailed characteristics in different operational parameters are also discussed.

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We design a fiber-optic cavity based on semiconductor optical amplifier gain medium. As the continuous-wave lasing phenomenon results from the stimulated amplification of photons at the frequencies close to the peak of intracavity net gain, the observation of narrowing and redshift of the spectrum by tuning pump current that may signature the formation of photon BEC.

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A direct laser patterning process was proposed to prepare transparent organic photovoltaics (OPVs) with high power conversion efficiency (PCE). Besides the transparency of the devices, the device’s PCE was also kept at over 10%. As a result, such a process can pattern the feature of the OPV, which tunes the transmittance value according to its patterned shape. We believe that our proposed device can achieve the average visible transmission value of > 70% if we reduce the pattern space with a micro-scale.

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