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Antimonene, a new member of monoelemental two‐dimensional crystals composed of antimony atoms, was predicted to possess high stability, as well as outstanding electrical and optical properties. Here, we report on the experimental results of productive, high‐quality synthesis of antimonene quantum dots (AQDs) via liquid‐phase exfoliation. The obtained AQDs exhibited excellent nonlinear saturable absorption. The modulation depth and the saturable intensity were found to be around 3.9% and 10.02 GW/cm2, respectively. By using the AQDs saturable absorber in the 639 nm Pr:YLF laser, stable Q‐switching pulsed laser was realized. The maximum output power was 83 mW and the corresponding pulse width was 255 ns with a pulse repetition rate of 227 kHz. These results suggest that AQDs are a promising candidate for nonlinear optical applications.

Intergranular corrosion is considered the major cause of the embrittlement of archaeological silver artifacts. However, the galvanic attack between different phases is a rather complex process involving the differences in local electrochemical activities that have been proved difficult to further understand with existing techniques. Herein, a visualized quantitative procedure of studying intergranular corrosions is established in this work through the preparation of a simulated silver–copper alloy sample and application of the scanning electrochemical cell microscopy (SECCM) as a high spatial resolution method. The macroscopic corrosion behavior according to the droplet corrosion tests is highly consistent with the results of local electrochemical activities acquired from SECCM. Meanwhile, the possibility of studying intergranular corrosion behavior in different soil environments by SECCM is demonstrated through a corrosion test under standardized ion conditions, which indicates a bright future of this method in the field of corrosions.

Monolithic optical parametric oscillators extend laser frequencies in compact architectures, but normally guide and circulate all pump, signal, and idler beams. Critical frequency matching is raised among these resonances, limiting operation stability and continuous tuning. Here, we develop a box resonator geometry that guides all beams but only resonates for signal. Such noncritical frequency matching enables 227 GHz continuous tuning, with sub-10 kHz linewidth and 0.43 W power at 3310 nm. Our results confirm that monolithic resonator can be effectively used as a tunable laser including midinfrared wavelength, as further harnessed with methane fine spectral measurement at MHz accuracy.

Single longitudinal mode and single polarization are basic requirements of high performance fiber lasers, while their realizations are nontrivial, owing to the long laser cavity and lack of polarization selection of ordinary optical fibers. Here, we demonstrate an all-fiber narrow-linewidth laser realized on an external high-Q fiber ring, with combined functions of single-longitude-mode selection and linewidth reduction. A single-longitude-mode laser with a high polarization extinction ratio of ∼ 40 d B and low white frequency noise at 0.3 H z 2 / H z is achieved, corresponding to a fundamental linewidth of ∼ 0.92 H z . Using all non-polarization fiber components and ordinary gain fiber, our scheme shows the realization of narrow-linewidth single-polarization fiber lasers in a simple and cost-effective way, promising for broadband applications.

We demonstrate a compact, high efficiency and widely tunable intracavity singly resonant optical parametric oscillator (IC-OPO) based on multichannel periodically poled lithium niobate (PPLN). The IC-OPO is composed of 808 nm pump laser diode (LD), Nd:YVO4 laser and linear OPO. The continuous-wave (CW) mid-infrared (MIR) output laser is tunable from 2.25 to 4.79 μm. The maximum output power exceeds 1.08 W at 3.189 μm at 9.1 W LD pump power and the conversion efficiency is 11.88%. We also build up a prototype with volume of 145 × 85 × 42.5 mm3 and its total weight is less than 2 kg. The measured power stability is 1.3% Root Meat Square (RMS) for a 3 h duration under simulated high temperature conditions of 40 °C. RMS is 2.6% for a 4 h duration when simulated temperature is − 40 °C.

Electrically controllable laser frequency combs are achieved in a 10 GHz graphene heterogeneous fiber microcavity. It demonstrates tunable mode-locking states with half-an-octave span and phase noise down to -120 dBc/Hz at 10 kHz.

Hyperparametric oscillation is essential for coherent optical signal generation in a broad wavelength range. Integration in a compact system, such a broadband light source, is of special interest for practical applications requiring field-deployable spectroscopy devices. Here we demonstrate an all-fiber hyperparametric oscillation source based on four-wave mixing in a high-Q fiber Fabry&ndash, P&eacute, rot (FFP) microresonator. Assisted by the Raman effect, the generated optical signal spans over 400 nm with fine line-to-line spacing of 667 MHz. The compatibility of this FFP microresonator enables a robust and reliable all-fiber system through a splicing technique and fiber connectors. Such a plug-and-play platform is convenient and efficient for broad applications in optical communications and spectroscopy.

Optical parametric oscillators (OPOs) can downconvert the pump laser to longer wavelengths with octave separation via χ ( 2 ) , which is widely used for laser wavelength extension including mid-infrared (MIR) generation. Such a process can be integrated in monolithic resonators, being compact and low in threshold. In this work, we show that the monolithic χ ( 2 ) mini-OPO can also be used for optical frequency comb generation around 2096 nm and enters the boundary of MIR range. A new geometry called an optical superlattice box resonator is developed for this realization with near-material-limited quality factor of 4.0 × 10 7 . Only a continuous-wave near-infrared pump laser is required, with OPO threshold of 80 mW and output power up to 340 mW. Revival temporal profiles are measured at a detectable repetition frequency of 1.426 GHz, and narrow beat note linewidth of less than 10 Hz shows high comb coherence. These results are in good agreement with our simulation for a stable comb generation. Such an OPO-based comb source is useful for carbon dioxide sensing or the mine prospect applications and can be generalized to longer MIR wavelengths for general gas spectroscopy.

We experimentally demonstrate a Kerr frequency comb from a fiber Fabry-Pérot(FP) microresonator that is pump by a self-injection locked distributed feedback diode laser. The comb span exceeds 80 nm around 1550 nm, with beatnote linewidth of 370Hz.

We demonstrate a Kerr soliton comb generation from a high-quality-factor fiber Fabry- Perotmicroresonator. Single soliton can be achieved, with narrow beatnote linewidth and nearquantum-noise-limited low phase noise.

We demonstrate 2 pm frequency comb generation via optical parametric down conversion from a high-quality-factor x(2) optical superlattice box resonator. Low noise comb is achieved with high output power.

Layered transitional metal dichalcogenides (TMDs) are drawing significant attentions for the applications of optics and optoelectronics. To achieve optimal performances of functional devices, precisely controlled doping engineering of 2D TMDs alloys has provided a reasonable approach to tailor their physical and chemical properties. By the chemical vapor transport (CVT) method and liquid phase exfoliation technique, in this work, we synthesized WS1.76Te0.24 saturable absorber (SA) which exhibited high-performance of nonlinear optics. The nonlinear saturable absorption of the WS1.76Te0.24 SA was also measured by the open aperture Z-scan technique. Compared to that of the binary component WS2 and WTe2, WS1.76Te0.24 SA has shown 4 times deeper modulation depth, 28% lower saturable intensity and a much faster recovery time of 3.8 ps. The passively Q-switched laser based on WS1.76Te0.24 was more efficient, with pulse duration narrowed to 18%, threshold decreased to 28% and output power enlarged by 200%. The promising findings can provide a method to optimize performances of functional devices by doping engineering.

Photonic sensors that are able to detect and track biochemical molecules offer powerful tools for information acquisition in applications ranging from environmental analysis to medical diagnosis. The ultimate aim of biochemical sensing is to achieve both quantitative sensitivity and selectivity. As atomically thick films with remarkable optoelectronic tunability, graphene and its derived materials have shown unique potential as a chemically tunable platform for sensing, thus enabling significant performance enhancement, versatile functionalization and flexible device integration. Here, we demonstrate a partially reduced graphene oxide (prGO) inner-coated and fiber-calibrated Fabry-Perot dye resonator for biochemical detection. Versatile functionalization in the prGO film enables the intracavity fluorescent resonance energy transfer (FRET) to be chemically selective in the visible band. Moreover, by measuring the intermode interference via noise canceled beat notes and locked-in heterodyne detection with Hz-level precision, we achieved individual molecule sensitivity for dopamine, nicotine and single-strand DNA detection. This work combines atomic-layer nanoscience and high-resolution optoelectronics, providing a way toward high-performance biochemical sensors and systems.

Optical microcavities have been widely used in nonlinear optics, quantum optics, and laser technologies. Here we demonstrate the self-injection locking of a distributed feedback diode laser using home-made high-finesse Fabry-Perot microcavity. The Fabry-Perot microcavity is fabricated from an x-cut lithium niobate crystal with highly reflective coatings. Frequency pulling effect can be observed for a successful locking, and results in a single-longitudinal mode lasing with narrow linewidth. The lasing wavelength and output power are found robust to the laser-diode current and temperature variations, in comparison to the free-running case. We further characterize the laser linewidth with beat note measurement with a high-performance external cavity diode laser, with beat-note linewidth of 601.85 kHz. This results shows a new method for laser frequency stabilization in a simple setup, and may find applications in telecommunication and spectroscopy.

We study the effect of waveguide thickness variations on the frequency spectrum of spontaneous parametric down-conversion in the periodically-poled lithium niobate on insulator (LNOI) waveguide. We analyze several variation models and our simulation results show that thickness variations in several nanometers can induce distinct effects on the central peak of the spectrum, such as narrowing, broadening, and splitting. We also prove that the effects of positive and negative variations can be canceled and thus lead to a variation-robust feature and an ultra-broad bandwidth. Our study may promote the development of on-chip photon sources in the LNOI platform, as well as opensup a way to engineer photon frequency state.

Metal–semiconductor junctions are at the heart of modern electronics. Various two-dimensional materials (2D) based electronic devices have been reported. However, Ohmic contacts between evaporated metal contacts and semiconducting 2D materials are still hard to achieve. Thus, design and fabrication of Schottky diodes based on layered WSe2 remain challenging. Here, we report a doping-free strategy to achieve Ohmic contacts in WSe2 diodes via van der Waals (vdW) contacts. We designed and fabricated vertical WSe2/Pd Schottky diodes, in which Ohmic and Schottky junctions can be realized simultaneously via vdW contacts and evaporated contacts, respectively. The specific contact resistance of the vdW contact is about 74.5 kΩ·μm2. The Schottky diodes exhibit strong rectification behavior with rectification ratio up to 105.

We demonstrate a broadband optical parametric oscillation, using a sheet cavity, via cavity phase-matching. A 21.2 THz broad comb-like spectrum is achieved, with a uniform line spacing of 133.0 GHz, despite a relatively large dispersion of 275.4 fs2/mm around 1064 nm. With 22.6% high slope efficiency, and 14.9 kW peak power handling, this sheet optical parametric oscillator can be further developed for χ (2) comb.

Mid-infrared (MIR) radiation is essential for remote gas sensing, ranging, and lidar applications, where high pulse energy and narrow linewidth are the keys to the high sensitivity over long distance. However, complex optical and electronic locking schemes are normally required to achieve both features at the same time. Here, we demonstrate pulse-pumped single-longitudinal-mode (SLM) MIR generation using a microresonator seed in the form of a sheet optical parametric oscillator (SOPO). The SOPO features a sub-coherence-length thickness of 400 µm, which enables SLM and high-energy oscillation using cavity phase matching. Its output around 1.55 µm is seeded into an optical parametric amplifier and locks the MIR output in SLM at 3.38 µm. In a simple and compact setup, up to 21% conversion efficiency and 22% slope efficiency are measured with a MIR output energy of 54 µJ. This SLM MIR source with the SOPO seed greatly reduces the system size and is compatible for further integration for field-deployable devices and thus has broad applications in the field of remote gas sensing.

Partially-reduced graphene oxide (prGO) inner-coated and fiber-calibrated Fabry-Perot dye resonator for biochemical detection enables the functionalized FRET-gain-assistance and intermode heterodyne interference, we achieve individual molecule sensitivity for dopamine, nicotine and ssDNA.

We report χ(2) and χ(3) frequency up-conversion in silicon nitride microcavities. Pumped by C-/L- band, a broadband frequency conversion from 437 nm to 816 nm is obtained based on regenerative satellite comb structures, with χ(2) process supported by nitride-oxide surface symmetry breaking.

We demonstrate the first mid-infrared frequency comb generation via optical parametric down conversion from a high-Q χ(2) optical superlattice box resonator. Low noise comb is achieved with high output power.

Narrow-linewidth lasers are essential for various applications, but are limited by their size, weight, power, and cost requirements. Here we demonstrate a self-injection locked diode laser fabricated with a high quality factor fiber Fabry–Perot resonator, with a 145 Hz free-running linewidth. The locking scheme is all-fiber for plug-and-play operation. White frequency noise of 50 H z 2 / H z is measured with over 42 dB reduction from the low-cost TO-can distributed feedback laser diode, and shows its wide applications in a compact and cost-effective way.

We study the effect of dimension variation for second-harmonic generation (SHG) in lithium niobate on insulator (LNOI) waveguides. Non-trivial SHG profiles in both type-0 and type-I quasi-phase matching are observed during the wavelength tuning of the fundamental light. Theoretical modeling shows that the SHG profile and efficiency can be greatly affected by the waveguide cross-section dimension variations, especially the thickness variations. In particular, our analysis shows that a thickness variation of tens of nanometers is in good agreement with the experimental results. Such investigations could be used to evaluate fabrication performance of LNOI-based nonlinear optical devices.

We demonstrate a tunable optical parametric oscillator in a periodically poled congruently grown lithium tantalite whispering gallery mode resonator. The resonator is mechanically polished to millimeter size, and the quality factor is approximately 107 at 1064 nm. Our experiments show that this kind of resonator is capable of reaching a very low threshold and having a wide tuning range. Combined with its narrow resonant linewidth, it is potentially used as a compact, widely tunable, and narrow-linewidth infrared to mid-infrared laser source.

Multiphoton absorption (MPA) has been utilized for important technological applications. High-order multiphoton harvesting (e.g., five-photon absorption, 5PA) exhibits unique properties that could benefit biophotonics. Within this field, perovskite oxide ferroelectrics (e.g., BaTiO3 ) enable low-order optical nonlinearities of 2PA/3PA processes. However, it is challenging to obtain efficient, high-order 5PA effects. Herein, for the first time, giant and broadband MPA properties are presented in the 2D hybrid perovskite ferroelectric (IA)2 (MA)2 Pb3 Br10 (1; IA = isoamylammonium and MA = methylammonium), where multiphoton-excited optical nonlinearities related to different MPA mechanisms over a broadband range of 550-2400 nm are observed. Strikingly, its 5PA absorption cross-section (σ5 ) reaches up to 1.2 × 10-132 cm10 s4 photon-4 (at 2400 nm), almost 10 orders larger than some state-of-the-art organic molecules and a record-high value among all known ferroelectrics. This unprecedented 5PA effect results from the quantum-confined motif of inorganic trilayer sheets (wells) and organic cations (barriers) in 1. Moreover, its large ferroelectric polarization of 5 µC cm-2 could promote modulation of MPA effects under external electric fields. As far as it is known, this is the first report on giant, broadband high-order MPA properties in ferroelectrics, which provides potential, novel electric-ordered materials for next-generation biophotonic applications.

Lithium niobate on insulator (LNOI) is a unique platform for integrated photonic applications and especially for high-efficiency nonlinear frequency converters because of the strong optical field confinement. In this work, we fabricated a 6-mm-long periodically poled LNOI ridge waveguide with an optimized duty cycle (50:50) using an active domain structure monitoring method. The performance of the single-pass second-harmonic generation and difference-frequency generation in the nanophotonic waveguide was characterized, and the normalized conversion efficiencies were ∼80% of the theoretical values. These high-quality frequency conversion devices can pave the way for the application of LNOI in nonlinear integrated photonics.

Alloying in two-dimension has been a hot spot in the development of new, versatile systems of optics and electronics. Alloys have been demonstrated to be a fascinating strategy to modulate the chemical and electronic properties of two-dimensional nanosheets. We firstly reported ultra-broadband enhanced nonlinear saturable absorption of Mo0.53W0.47Te2 alloy at 0.6, 1.0, and 2.0 μm. The nonlinear saturable absorption of Mo0.53W0.47Te2 saturable absorber (SA) was measured by the open aperture Z-scan technique. Compared to MoTe2 and WTe2 SAs, the Mo0.53W0.47Te2 SA showed five times deeper modulation depth, 8.6% lower saturable intensity, and one order larger figure of merit. Thus, our research provides a method of alloys to find novel materials with more outstanding properties for optics and optoelectronic applications.

We demonstrated the efficient plasmon-induced nonlinear absorption of liquid metal GaInSn nanospheres prepared by a facile liquid-phase method. With GaInSn as saturable absorbers, a passively Q-switching operation was obtained at both 1.3 and 2 μm. The pulse width of 32 ns was achieved at 1.3 μm with repetition rate of 44 kHz, single pulse energy of 51.9 μJ, and output power of 425 mW. Meanwhile, 510 ns and 92 kHz pulses with energy of 36.1 μJ and output power of 2.48 W were obtained at 2 μm. This work provides the potential of liquid metal for improving metal functions and flexible optical devices.

We demonstrate here a compact optical parametric oscillator module for mid-infrared generation via nonlinear frequency conversion. This module weighs only 2.5 kg and fits within a small volume of 220 × 60 × 55 mm3. The module can be easily aligned to various pump laser sources, and here we use a 50 W ytterbium (Yb)-doped fiber laser as an example. With a two-channel MgO-doped periodically poled lithium niobate crystal (MgO:PPLN), our module covers a tuning range of 2416.17–2932.25 nm and 3142.18–3452.15 nm. The highest output power exceeds 10.4 W at 2.7 μm, corresponding to a conversion efficiency of 24%. The measured power stability is 2.13% Root Meat Square (RMS) for a 10 h duration under outdoor conditions.

Graphene, a unique two-dimensional material comprising carbon in a honeycomb lattice 1 , has brought breakthroughs across electronics, mechanics and thermal transport, driven by the quasiparticle Dirac fermions obeying a linear dispersion 2,3 . Here, we demonstrate a counter-pumped all-optical difference frequency process to coherently generate and control terahertz plasmons in atomic-layer graphene with octave-level tunability and high efficiency. We leverage the inherent surface asymmetry of graphene for strong second-order nonlinear polarizability 4,5 , which, together with tight plasmon field confinement, enables a robust difference frequency signal at terahertz frequencies. The counter-pumped resonant process on graphene uniquely achieves both energy and momentum conservation. Consequently, we demonstrate a dual-layer graphene heterostructure with terahertz charge- and gate-tunability over an octave, from 4.7 THz to 9.4 THz, bounded only by the pump amplifier optical bandwidth. Theoretical modelling supports our single-volt-level gate tuning and optical-bandwidth-bounded 4.7 THz phase-matching measurements through the random phase approximation, with phonon coupling, saturable absorption and below the Landau damping, to predict and understand graphene plasmon physics. An all-optical difference frequency process is exploited to generate terahertz graphene plasmons that are tunable over an octave.

The MoS 2 /Graphene heterojunction prepared through a facile hydrothermal method is used as an optical modulator to realize 2.8 μm passively Q-switched solid state pulse laser for the first time as far as we know. This work certifies that the two-dimensional material heterojunction is a kind of outstanding mid-infrared modulators.

We demonstrate a widely-tunable mid-infrared optical parametric oscillator in a monolithic periodically poled lithium Tantalate whispering-gallery-mode resonator. Low-threshold oscillation is achieved with 57.6% slope efficiency, covering the spectral range from 1.7 to 2.85μm.

Due to the composition-dependent properties of two-dimensional (2D) transition metal dichalcogenides (TMDs), alloying of existing dissimilar TMDs architecture is a novel and controllable route to tailor crystal structures with superior optical and optoelectronic properties. Here, we reported the hexagonal-phase WSe1.4Te0.6 alloy can enable great promise for enhanced saturable absorption response exceeding the parent component WSe2 and WTe2, with larger modulation depth and lower saturable intensity. These advantages allowed the 1064 nm passively Q-switched lasers based on WSe1.4Te0.6 to be more efficient, with pulse duration narrowed to 45%, and slope efficiency increased by 232%. Our findings highlighted the appropriate alloying of TMDs as an effective strategy for development of saturable absorbers.

We demonstrate a method to substantially increase the observation duty ratio in temporal-magnification system without sacrificing the temporal resolution. 30% or even 100% observation duty ratio can be achieved on a 10-ns or longer waveform.

We demonstrate a graphene-alumina-graphene heterostructured semiconductor chip, on which THz plasmons are generated via backward phase-matched 2nd nonlinearity all-optically. The on-chip plasmons are effectively gate tunable, with photon-efficiency ∼10−4, and Q factor > 60.

We demonstrate a high efficiency mid-infrared laser source based on optical parametric oscillator (OPO) assisted by an intracavity optical parametric amplification (OPA). The OPA-assisted-OPO scheme was realized in one piece of commensurable dual-periodic superlattice in which the signal light generated from the OPO process serves as the pump light for the OPA process. A maximum output power of 508 mW at 3.92 μm was achieved under a pump power of 2.85 W at 1.064 μm. The pump-to-idler conversion efficiency is 17.8% and the slope efficiency is 23.8%, and the enhancements of them are 58.9% and 67.6%, respectively, comparing with the standard OPO scheme.

WTe2 is a unique material in the family of transition metal dichalcogenides and it has been proposed as a candidate for type-II Weyl semimetals. However, thus far, studies on the optical properties of this emerging material have been significantly hindered by the lack of large-area, high-quality WTe2 materials. Here, we grow a centimeter-scale, highly crystalline WTe2 ultrathin film (∼35 nm) by a pulsed laser deposition technique. Broadband pump-probe spectroscopy (1.2–2.5 μm) reveals a peculiar ultrafast optical response where an initial photo-bleaching signal (lasting ∼3 ps) is followed by a long-lived photoinduced absorption signature. Nonlinear absorption characterization using femtosecond pulses confirms the saturable absorption response of the WTe2 ultrathin films, and we further demonstrated a mode-locked Thulium fiber laser using a WTe2 absorber. Our work provides important insights into linear and nonlinear optical responses of WTe2 thin films.

We report the fabrication of an MoS2 black phosphorus (BP) composite saturable absorber by liquid phase exfoliation and the spin-coating method and further exploitation to build a 2 μm passively Q-switched Tm:YAP laser. Such a composite based Q-switched laser with a duration of 488 ns and corresponding peak power of 85.9 W is obtained, which shows an improved saturable absorption effect than that of single MoS2 (616 ns, 68.7 W) and BP (932 ns, 22.4 W). The results indicate that simple and reasonable fabrication of the vertical composite from two-dimensional atomic layer materials opens up the possibility to create an unprecedented saturable absorber with exciting properties.

High-power blue light was generated from a diode-side-pumped Q-switched 1319 nm Nd:YAG laser with a periodically poled, stoichiometric LiTaO3 (PPSLT) crystal. The PPSLT sample used in this experiment consists of two segments in series: the first segment has a period of 14.08 μm for the second harmonic generation (SHG) and the second segment has periods of around 4.6 μm for the generation of blue light by mixing fundamental and SH. An average power of 466 mW of a 440 nm blue light was obtained at the fundamental power of ∼5.4 W with a conversion efficiency of 8.6%. The output power fluctuated by 3% over a half-hour period. This result indicates that our scheme is a practical method to construct a reliable compact blue laser.

We demonstrate single-photon frequency-upconversion using a titanium-infused periodically-poled lithium niobate waveguide by L-band erbium-doped fiber amplifier pump. Internal efficiencies up to 84.4% and dark-count rate of 44kHz are achieved with narrowband filtering down to 3.5GHz.

We demonstrate simultaneous lasing and parametric oscillation with high-Q (> 1010) MgF 2 monolithic microresonators. Stable lasing around 698nm is achieved with sub-25kHz linewidth and 8.8nm tuning range. Multi-pair hyperparametric oscillation is observed over 137.2THz span.

We report an efficiency-enhanced mid-infrared generation via optical parametric down conversion. A tandem periodically-poled MgO-doped stoichiometric lithium tantalate crystal is used to realize on-chip generation and amplification of mid-infrared radiation inside an optical parametric oscillator cavity. We achieved 21.2% conversion efficiency (24% slope efficiency), which is among the highest efficiencies for the pump-to-mid-infrared conversion, with 1064 nm Nd class laser pump. The maximum average output power at 3.87 μm reached 635 mW with a 3.0 W pump.

Cavity phase matching has been recently demonstrated as a phase-matching method for efficient nonlinear frequency conversion in a microcavity. Here we extend it to the Type I configuration using a sub-coherent-length optical parametric oscillator consisting of an MgO-doped lithium niobate crystal sheet. It generates a tunable single-longitudinal-mode twin beam, which covers the cesium D2 line of 852.1 nm and the extended band of optical communication. This microcavity is capable of peak output power of 58 kW with a maximum conversion efficiency of 18.5%. Broad applications in the areas of light-atom interaction, spectroscopy, optical telecommunication, and quantum optics can be expected.

We experimentally demonstrate a compact, all-solid-state 532 nm semi-Gaussian laser beam (SGB) source based on a 1064 nm laser and a transversely varying periodically-poled LiTaO3 (TPPLT) crystal as the laser beam shaper as well as the nonlinear frequency converter. We have used the designed TPPLT crystal to obtain a neat 532nm SGB with the quality of QSGB=1:17.5 by a single-pass second harmonic generation. The dependence of the generated SGB quality on the designed TPPLT parameter and the potential applications of the neat SGB are also discussed.

We theoretically studied nonlinear interactions between surface plasmon polariton (SPP) and conventional waveguide mode in nonlinear hybrid waveguide and proposed a possible method to enhance SPP wave via optical parametric amplification (OPA). The phase matching condition of this OPA process is fulfilled by carefully tailoring the dispersions of SPP and guided mode. The influences of incident intensity and phase of guided wave on the OPA process are comprehensively analyzed. It is found that not only a strong enhancement of SPP but also modulations on this enhancement can be achieved. This result indicates potential applications in nonlinear optical integration and modulations.

In this Letter, we demonstrate a nonlinear-mirror (NLM) mode-locked diode-pumped solid-state Nd:YVO4 laser operating at 1342 nm, in which the NLM comprises a periodically poled LiNbO3 crystal and a dichroic mirror. The self-starting threshold for cw mode locking is 1.5 W, which is significantly lower than that of saturable absorber mode locking. An average power of 1.52 W at 1342 nm is obtained under diode pump power of 10 W at 808 nm, with the slope efficiency being up to 16.8%. The pulse width and the repetition rate of the mode-locked laser output are about 9.5 ps and 101 MHz, respectively.

We demonstrate a compact all-solid-state yellow laser source based on Q-switched dual-wavelength Nd:YAG laser and periodically-poled LiTaO(3) crystal. 589-nm yellow light was generated by single-pass sum-frequency generation of the fundamental IR waves at 1064 and 1319 nm. The maximum output power of yellow light was 506 mW and the corresponding conversion efficiency was approximately 5.5% [W(-1)cm(-1)].