Background: Patients with recurrent or metastatic advanced colorectal cancer (mCRC) often face the clinical dilemma as this unresectable disease is continuously progressing and endangering the patients' lives. In the current study, we explored the clinical feasibility of KH903 in combination with FOLFIRI chemotherapy as a new clinical indication for mCRC.
Methods: Patients (N = 122) were randomized 1:1 to 4mg/kg q1w KH903 or 5mg/kg q2w KH903, and both groups of patients were treated with the fixed regimen of FOLFIRI (every 2 weeks) along with the KH903 therapy.
Spectral evolution in nonlinear optical processes, such as second harmonic generation (SHG) and sum frequency generation (SFG), plays a crucial role in multi-wavelength generation through nonlinear frequency conversion. In this study, the enhancement of spectral performance in a multi-wavelength visible laser facilitated by SHG-SFG hybrid processes is proposed and demonstrated, for the first time to our knowledge. An output of up to eleven wavelengths can be achieved using a six-wavelength pump.
View Article and Find Full Text PDFThe primary focus of this article centers around the application of sliding mode control (SMC) to semi-Markov jumping systems, incorporating a dynamic event-triggered protocol (ETP) and singular perturbation. The underlying semi-Markov singularly perturbed systems (SMSPSs) exhibit mode switching behavior governed by a semi-Markov process, wherein the variation of this process is regulated by a deterministic switching signal. To simultaneously reduce the triggering rate and uphold the system performance, a novel parameter-based dynamic ETP is established.
View Article and Find Full Text PDFThis study presents a high-accuracy, all-fiber mode division multiplexing (MDM) reconstructive spectrometer (RS). The MDM was achieved by utilizing a custom-designed 3 × 1 mode-selective photonics lantern to launch distinct spatial modes into the multimode fiber (MMF). This facilitated the information transmission by increasing light scattering processes, thereby encoding the optical spectra more comprehensively into speckle patterns.
View Article and Find Full Text PDFIn a fiber supercontinuum (SC) source, the Raman scattering effect plays a significant role in extending the spectrum into a longer wavelength. Here, by using a phosphorus-doped fiber with a broad Raman gain spectrum as the nonlinear medium, we demonstrate flat SC generation spanning from 850 to 2150 nm. Within the wavelength range of 1.
View Article and Find Full Text PDFLow-coherence tunable visible light sources have a wide range of applications in imaging, spectroscopy, medicine, and so on. Second harmonic generation (SHG) based on a superfluorescent fiber source (SFS) can produce high-brightness visible light while retaining most of the characteristics of superfluorescent sources, such as low coherence, low intensity noise and flexible tunability. However, due to the limitations in phase matching conditions, SHG based on SFS is difficult to reach an equilibrium between high efficiency and robustness of phase matching to temperature variation.
View Article and Find Full Text PDFDevelopment of a high power fiber laser at special waveband, which is difficult to achieve by conventional rare-earth-doped fibers, is a significant challenge. One of the most common methods for achieving lasing at special wavelength is Raman conversion. Phosphorus-doped fiber (PDF), due to the phosphorus-related large frequency shift Raman peak at 40 THz, is a great choice for large frequency shift Raman conversion.
View Article and Find Full Text PDFRaman fiber laser (RFL) has been widely adopted in astronomy, optical sensing, imaging, and communication due to its unique advantages of flexible wavelength and broadband gain spectrum. Conventional RFLs are generally based on silica fiber. Here, we demonstrate that the phosphosilicate fiber has a broader Raman gain spectrum as compared to the common silica fiber, making it a better choice for broadband Raman conversion.
View Article and Find Full Text PDFNanomaterials (Basel)
April 2022
The phosphosilicate fiber-based Raman fiber laser (RFL) has great potential in achieving low-quantum defect (QD) high-power laser output. However, the laser's performance could be seriously degraded by the Raman-assisted four-wave mixing (FWM) effect and spontaneous Raman generation at 14.7 THz.
View Article and Find Full Text PDFThe random Raman fiber laser (RRFL) has attracted great attention due to its wide applications in optical telecommunication, sensing, and imaging. The quantum defect (QD), as the main source of thermal load in fiber lasers, could threaten the stability and reliability of the RRFL. Conventional RRFLs generally adopt silica fiber to provide Raman gain, and the QD exceeds 4%.
View Article and Find Full Text PDFDue to the beam cleanup effect, brightness enhancement (BE) can be achieved in a Raman fiber amplifier (RFA) based on multimode (MM) graded-index (GRIN) fiber. In this Letter, a novel, to the best of our knowledge, diagnostic tool of mode decomposition (MD) based on a stochastic parallel gradient descent algorithm is demonstrated to observe the beam cleanup effect in a GRIN-fiber-based RFA for the first time, to our knowledge. During output power boosting up to 405 W at 1130 nm, the output beam quality factor improves from 3.
View Article and Find Full Text PDFThe power scaling on all-fiberized Raman fiber oscillator with brightness enhancement (BE) based on multimode graded-index (GRIN) fiber is demonstrated. Thanks to beam cleanup of GRIN fiber itself and single-mode selection properties of the fiber Bragg gratings inscribed in the center of GRIN fiber, the efficient BE is realized. For the laser cavity with single OC FBG, continuous-wave power of 334 W with an M value of 2.
View Article and Find Full Text PDFIn this Letter, we demonstrate a high-power Raman fiber amplifier with excellent beam quality based on graded-index fiber. The Yb-doped fiber laser (YDFL) and bandwidth-tunable amplified spontaneous emission (ASE) source are employed as the pump source to compare the laser performance separately. When the ASE with a bandwidth of 8 nm is employed, a maximum power of 943 W at 1130 nm is achieved, which is twice that pumped by YDFL.
View Article and Find Full Text PDFQuantum defect (QD)-induced high thermal load in high-power fiber lasers can largely affect the conversion efficiency, pose a threat to the system security, and even prohibit the further power scaling. In this Letter, we investigate evolutions and influences of the reflectivity of the output coupler, the length of phosphosilicate fiber, and the pump bandwidth, and demonstrate a hundred-watt-level low-QD Raman fiber laser (RFL). The RFL enabled by the boson peak of phosphosilicate fiber achieves a maximum power of 100.
View Article and Find Full Text PDFMultiwavelength fiber lasers, especially those operating at optical communication wavebands such as 1.3 μm and 1.5 μm wavebands, have huge demands in wavelength division multiplexing communications.
View Article and Find Full Text PDFFour-wave mixing induced spectral broadening near the zero-dispersion wavelength (ZDW) of the fiber is a bottleneck factor that limits the further wavelength extending in cascaded random fiber lasers (RFLs). In this Letter, we successfully suppress the spectral broadening near the ZDW of the fiber in the cascaded RFL by simply combining two kinds of commercial telecom fibers with different ZDWs, G655C fiber with ZDW around 1.52 µm and G652D fiber with ZDW around 1.
View Article and Find Full Text PDFWe comprehensively study the effects of temporal and spectral optimization on single-mode Raman fiber amplifiers. Amplified spontaneous emission sources and ytterbium-doped fiber lasers are employed as seed or pump lasers for comparison, and passive fibers are utilized as gain media. The influences of various parameters of the laser on 2 order Raman threshold and maximum output power are investigated experimentally, including bandwidth, seed power, wavelength separation between pump and seed laser, and temporal stability.
View Article and Find Full Text PDFA flat-amplitude multi-wavelength random Raman fiber laser with broad spectral coverage and a high optical signal-to-noise ratio (OSNR) is challenging and of great interest. In this Letter, we theoretically and experimentally proved that broadband pumping can help realize a broader, flat-amplitude multi-wavelength random Raman fiber laser. The influence of pump bandwidth, tunability of the spectral envelope, and channel spacing are investigated.
View Article and Find Full Text PDFOwing to the special power distribution property, a random distributed feedback Raman fiber laser can achieve a high power spectrally flexible output with a low power spectrally tuning device. Here, an all-fiberized linearly polarized dual-wavelength random distributed feedback Raman laser with wavelength, linewidth, and power ratio tunability is demonstrated. By adopting two watt-level bandwidth adjustable optical filters, a spectrum-manipulable dual-wavelength output with nearly a 10 W output power is achieved.
View Article and Find Full Text PDFCascaded random Raman fiber lasers (CRRFLs) with simple configuration and high spectral purity have become a great candidate for power scaling over the 1.1 µm-2 µm spectral band. Recently, CRRFLs with high spectral purity over 90% have been proposed by applying a highly temporal-stable pump source or a free-space short-pass filter, at the cost of increased system complexity.
View Article and Find Full Text PDFWe demonstrate a tunable, high order cascaded random Raman fiber laser (RRFL) with high purity at 1.7 µm band by using a high power amplified spontaneous emission source (ASE) with both wavelength and linewidth tunability as pump source. The influence of the spectral bandwidth of the ASE source on the spectral purity of the output at 1.
View Article and Find Full Text PDFPhosphosilicate fiber has the inherent advantage of generating dual-wavelength output owing to the two Raman gain peaks at the frequency shifts of ∼13.2 THz (silica-related) and 39.9 THz (phosphorus-related), respectively.
View Article and Find Full Text PDFIn this paper, an all-fiberized transverse mode-switching method was proposed based on temperature control of few-mode (FM) fiber Bragg gratings (FBGs). Two types of fibers were selected to fabricate the FBG pair in order to match the reflection peaks of the desired mode. The temperature-dependence property of the FM FBGs has been utilized to tune the reflection spectra.
View Article and Find Full Text PDFWe demonstrated a high-quality black phosphorus (BP) crystal fabricated a modified electrochemical delamination exfoliation process. Employing the nonlinear transmittance method and Z-scan technique, the nonlinear optical properties of BP were characterized. Based on the saturable absorber (SA) of BP, we designed a passively Q-switched ytterbium (Yb)-doped fiber laser operating at 1.
View Article and Find Full Text PDFRandom fiber laser based on Raman gain and random distributed feedback has drawn great attention in recent years. One of the most widely-studied fields is to improve the optical efficiency and the output power. However, the power scaling of a random fiber laser is instinctively restricted by the high order Stokes generation.
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