- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE 2018 25th International Conference "Mixed Design of Integrated Circuits and System" (MIXDES) - Gdynia, Poland (2018.6.21-2018.6.23)] 2018 25th International Conference "Mixed Design of Integrated Circuits and System" (MIXDES) - Optimization of Class-D Amplifier Output Stage for Piezoelectric Actuator Control
摘要： Design of a piezoelectric driver for a microelectromechanical actuator in a small form factor for laser telecommunications is introduced. The driver introduces a number of challenges due to its size and power limitations as a Microelectromechanical Systems (MEMS) actuator. Because of the small form factor, the driver must be integrated into the actuator itself, which limits its size and power. The efficiency of a linear amplifier becomes a major drawback due to the dissipated heat of only 20 W for the Laser Telecommunications Module (LTM), low efficiency of a linear amplifier becomes a major drawback due to the dissipated heat. Switching Class-E amplifiers provide exceptional efficiency compared to non-switching solutions at a price of high frequency harmonics, which allows for higher output power without additional heat dissipation. The efficiency, however, comes at a price of high frequency harmonics, which must be reduced by implementing a High-Energy-Efficiency Interference (HEEI) and Total Harmonic Distortion (THD). Driving a capacitive load, such as a piezoelectric actuator, at a high frequency with a Class-E amplifier requires a matching network to achieve the desired output power. The measurements were performed on a custom-made driver model for piezoelectric stack actuators with 270 V peak-to-peak voltage, 500 kHz switching frequency and a range of capacitive load from 2.1 nF to 20 nF.
关键词： Actuator,Driver,Amplifier,Distortion,LTM.2,Output Stage,SMPS,Class-E,Total,LTM,THD,MEMS,Harmonic,Transmission,Telecommunications,Laser,Module,High-Energy-Efficiency,HEEI,Interference,Piezoelectric,Microelectromechanical
更新于2025-09-23 15:22:29
-
In memory of Charles Kao
摘要： Optical fibre technology transformed telecommunications, leading to the global broadband Internet, and beyond. Charles Kuen Kao is the father of optical fibre communications whose vision changed the world.
关键词： Charles Kuen Kao,Nobel Prize in Physics,telecommunications,optical fibre
更新于2025-09-23 15:21:01
-
High Quality Entangled Photon Pair Generation in Periodically Poled Thin-Film Lithium Niobate Waveguides
摘要： A thin-film periodically poled lithium niobate waveguide was designed and fabricated which generates entangled photon pairs at telecommunications wavelengths with high coincidences-to-accidentals counts ratio CAR > 67000, two-photon interference visibility V > 99%, and heralded single-photon autocorrelation g(0) < 0.025. Nondestructive in situ diagnostics were used to determine the poling quality in 3D. Megahertz rates of photon pairs were generated by less than a milliwatt of pump power, simplifying the pump requirements and dissipation compared to traditional spontaneous parametric down-conversion lithium niobate devices.
关键词： lithium niobate waveguides,quantum information processing,entangled photon pairs,telecommunications wavelengths
更新于2025-09-23 15:19:57
-
Hybrid External Cavity Laser with an Amorphous Silicon-Based Photonic Crystal Cavity Mirror
摘要： The authors present results on the performance of a hybrid external cavity photonic crystal laser-comprising semiconductor optical ampli?er, and a 2D photonic crystal cavity fabricated in low-temperature amorphous silicon. The authors demonstrate that lithographic control over amorphous silicon photonic crystal cavity-resonant wavelengths is possible, and that single-mode lasing at optical telecommunications wavelengths is possible on an amorphous silicon platform.
关键词： nanophotonics,silicon photonics,amorphous silicon,CMOS processing,photonic crystals,telecommunications,lasers
更新于2025-09-16 10:30:52
-
Optical Fiber Communications (Principles and Applications) || WDM Concepts and Components
摘要： Wavelength division multiplexing (WDM) is the second major fiber–optic revolution in the field of telecommunications. WDM is a technology which combines many different segments of wavelength range, called different independent optical channels, into the same optical fiber. The best feature of an optical fiber is that it has a wide spectral region which ranges from 1260 nm to 1675 nm. The light source used in high-capacity optical fiber communication systems emits a narrow wavelength band of less than 1 nm, thus enabling simultaneous transmission of many optical channels using the same optical fiber. WDM allows a huge increase in capacity of an optical fiber as compared to point-to-point link that carries only a single optical channel. Another big advantage of WDM is that different transmission formats can be supported by various optical channels. It means that without the need of common signal format, any data rate can be transmitted simultaneously and independently using the common optical fiber.
关键词： optical fiber,wavelength channels,capacity upgrade,WDM,telecommunications
更新于2025-09-12 10:27:22
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Controllable Generation of Ultrashort Multi-Bound Solitons in a Mode-Locked Erbium-Doped Ring Laser with a Highly-Nonlinear Resonator
摘要： Mode-locked (ML) ultrashort pulse (USP) fiber lasers can be treated as an ideal platform to expand future applications due to a complex nonlinear dynamics with a presence of a high value of a group velocity dispersion and a third-order dispersion in the laser resonator. Up to now a series of novel ML regimes have been investigated e.g. self-similar pulses, noise-like pulses, multi-bound solitons, and a soliton rain generation. Multi-bound solitons (MBS) generation regime, also known as soliton molecules, is of considerable interest in various fields of applications. For example, the investigation of a MBS generation is very attractive for increasing the data transfer capacity in telecommunications due to coding alphabet extension. The coding concept of MBS suggests a data stream using more than two symbols (2?N symbols, where N is the number of generated solitons in a bound state) [1]. And also, recent research shows that using ultrafast bursts of pulses can improve the quality of laser ablation for medical applications [2]. Moreover, MBS generation can be also used in a coherent pulse staking amplification scheme increasing an amplification efficiency along with a formation of high-energy solitons at a high-repetition-rate [3]. Previously we have obtained a generation of stable low-noise ultrashort multi-bound solitons in a passive mode-locked all-fiber erbium-doped ring laser with a highly-nonlinear resonator [4]. Fig. 1 shows autocorrelation traces and spectrums of MBS generation obtained by pump power variation at a wavelength of 980 nm. The output spectrums are evidently showing high-contrast intensity fringes (up to ~20 dB) and autocorrelation traces having symmetrical form without additional intensity peaks that indicates a stable and strong coherent connection between ultrashort pulses and fixed coherent phase difference in the temporal domain between several identical pulses. It is known that the highest energy of a fundamental soliton in a laser resonator with duration τp is limited by the soliton area theorem Es ~ |β2|/(γ · τp), where γ is the net nonlinear coefficient and β2 is the total cavity dispersion [1]. Soliton energy quantization results in pulse splitting at operation powers higher than the fundamental limit. Here we experimentally demonstrate the formation multi-bound solitons with the controllable number of bound states 7 < N < 17 by pump power variation in the range from ~160 mW to ~377 mW obtained in a highly-nonlinear fiber ring cavity.
关键词： ultrashort pulse,laser ablation,fiber lasers,Mode-locked,coherent pulse staking amplification,soliton molecules,telecommunications,multi-bound solitons
更新于2025-09-12 10:27:22
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Hot-Cavity Spectroscopy of Dark Pulse Kerr Combs in Microresonators
摘要： Kerr frequency combs are generated through cascaded four-wave mixing in high-Q microresonators [1]. These devices are pumped with a continuous-wave laser and modulational instability (MI) is responsible for the growth of the initial comb lines. Since it is easier to satisfy the MI phase matching condition in the anomalous dispersion regime, most studies on Kerr combs have focused on anomalous dispersion microresonators. However, coherent microresonator combs can also take place in the normal dispersion regime. In these combs, phase matching is attained with the aid of the mode coupling between transverse modes of the microresonator [2]. One particularly interesting comb state that operates in the normal dispersion regime is the dark pulse Kerr comb [3]. The time domain pulses of these combs arise as interlocking switching waves that connect the upper and lower homogenous steady state solutions of the bi-stability curve in the continuous-wave-driven Kerr cavity [see Fig. (a)] [3]. These combs are of high interest as most nonlinear materials suitable for fabricating microresonators display normal dispersion in the visible and near infrared ranges. Moreover, these combs provide a much higher power conversion efficiency compared to bright-soliton combs, which makes them particularly useful for telecommunications [4]. Nevertheless, the formation of dark-pulse combs and their dynamics remain largely unexplored. In this work, we provide a better physical understanding of the formation of this type of combs by measuring the system’s response as the pump laser is tuned into resonance. We discover that the formation of the dark pulse Kerr combs is associated with the appearance of an extra resonance, in striking similarity to recent observations made for bright temporal solitons in the anomalous dispersion regime [5], and explain the findings based on cross-phase modulation (XPM) induced by the two homogeneous steady state solutions of the Kerr cavity.
关键词： dark pulse Kerr comb,microresonators,normal dispersion regime,Kerr frequency combs,telecommunications
更新于2025-09-12 10:27:22
-
Guiding light
摘要： Light trapped in hair-thin optical “wires” made of transparent materials such as glass can be piped around tight corners in computer chips, across oceans in telecommunications and back and forth inside a cavity in lasers. By eliminating beam diffraction, and allowing precise control over the beam shape and the chromatic dispersion, optical waveguides make many astonishing things possible.
关键词： dispersion,photonic crystal fibres,optical waveguides,diffraction,telecommunications,lasers
更新于2025-09-10 09:29:36