High Repetition Rate Pulse Generation Research Articles

Study on All-Solid High Repetition-Rate Pulse Generator Based on DSRD

The pulse generator based on drift step recovery diode (DSRD) has broad development prospects in the research of high pulse repetition frequency (PRF), high power pulse generators. In this letter, a pulse generator based on DSRD is successfully developed. The design of circuit topology and design principles are presented. The pulse generator can work stably outputting almost 30kV peak voltage at 100 kHz PRF or 140kV at 25kHz with a 50kΩ load. What's more, the influences of power supply voltage and load resistance are studied experimentally.

Mid-infrared high repetition mode-locked laser based on cross-band all-optical injection modulation

High speed pulse generation with adjustable output characteristics in the mid-infrared (MIR) wavelength is a challenge due to the lack of high speed optoelectronic modulator operating at this band. In this paper, we proposed a MIR actively mode-locked laser based on cross-band all-optical injection modulation. The proposed laser is modulated by injecting 1.55-μm pump pulses into the specially-designed cross-band group-velocity-matched fiber. By numerical simulation, we studied in detail the evolution mechanism of the pulses and the influence of the cavity parameters on the output pulse features. It is shown that the laser is suitable for high repetition rate pulse generation up to 40 GHz at 2.771 μm, and the pulse shape can be flexibly adjusted. The proposed MIR laser has great potential in MIR free-space optical (FSO) communication.

910-MHz, watt-level, signal-power-enhanced, compact femtosecond optical parametric oscillator based on bidirectional pumping technique

We propose a high-efficiency and compact 910-MHz femtosecond optical parametric oscillator, which is harmonically pumped by a ∼101 MHz Yb doped fiber laser system. The OPO is capable of delivering watt-level, power-enhanced signals across the telecommunication waveband. The signal power enhancement is realized by exploiting the bidirectional pumping technique. A maximum signal power of 1.04W at 1502nm is obtained for an input pump power of 3.8W. Tunable near-infrared signal pulses with a wavelength range between 1350 and 1610nm are measured, and the pulse durations vary from 193 to 464fs. This compact and economic design provides a solution for efficient high repetition rate pulse generation over a large wavelength span, which will be beneficial for a variety of practical applications.

Design of a 20-kHz High Repetition-Rate Magnetic Pulse Generator

Magnetic pulse compression (MPC) system has been widely used over a few decades as a technique for producing short duration, high peak power pulses reliably. Novel MPC system which do not contain external demagnetization circuits, have broadened the appliance of MPC systems, in which circuit in each level of storage energy capacitors is composed of two capacitors in series, and the two-capacitance combination is connected to the output of previous stage, so that not only the pulse is compressed but also the voltage is doubled as well. In this paper, a 20-kHz high repetition-rate pulse generator with adjustable output amplitude based on Novel MPC system is presented. The pulse generator makes use of commercially available insulated gate bipolar transistor (IGBT), switching a capacitor bank into a ferrite transformer together with a voltage doubling circuit. The capacitor bank is charged to 530 V by a three-phase rectifier, also switched by a commercial diode. The amplitude of the output voltage of the pulse generator is controlled by the amplitude of the gate voltage of the IGBTs. Pulses with a width of 70 ns can be generated with repetition rates up to 20 kHz in burst. The amplitude can be controlled from 5 to 40 kV into a $500~\Omega $ resistive load.

A megawatt solid-state modulator for high repetition rate pulse generation.

A novel solid-state modulator capable of generating rapid consecutive power pulses is constructed to facilitate experiments on plasma interaction with high power microwave pulses. The modulator is designed to output a 100 kHz tone burst, which consists of up to 10 pulses, each with 1 μs duration and 1 MW peak power. The pulses are formed by discharging a total of 480 μF capacitors through 24 synchronized MOSFETs and 6 step-up transformers. The highly modular design, as a replacement of an old single-pulse version used in earlier experiments which employs a pulse forming network, brings great flexibility and wide potential to its application. A systematic cost-effectiveness analysis is also presented.

High repetition-rate pulse generation for millimeter-wave pulse signal by two cascaded Gires–Tournois Interferometers

A simple optical approach is proposed to obtain millimeter-wave (MMW) pulse signal by the high repetition-rate pulse generation in two cascaded Gires–Tournois Interferometers (GTIs). Compared with single GTI, the cascaded GTIs can optimize the MMW pulse envelope and improve the performance of radio frequency (RF) signal by adjusting the space of cascaded GTIs to change the reflection times of optical propagating signal. The primary influences for the cascaded GTIs on MMW pulse are analyzed theoretically and measured experimentally. It is shown that the good agreement between experimental results and theoretical simulations verifies the feasibility and flexibility of the proposed scheme.

An 80-GHz chirp-free carrier-suppressed optical pulse generator using cascaded 20-GHz clock-driven Mach-Zehnder modulators

We propose and experimentally demonstrate a chirp-free carrier-suppressed optical pulse generator using a simple and cost-effective approach. An 80-GHz carrier-suppressed optical pulse train was successfully obtained by using two cascaded 20-GHz clock-driven dual-drive Mach-Zehnder modulators. Compared with the conventional scheme using 40-GHz clock driving signal to generate an 80-GHz pulse train, the proposed scheme is cost-effective and scalable to high repetition rate pulse generation by using low-speed devices.

High Energy and High Repetition Rate Pulse Generation Using Ytterbium-Doped Fiber

High Energy and High Repetition Rate Pulse Generation Using Ytterbium-Doped Fiber

Generation of 1 THz repetition rate, 97 fs optical pulse train based on comb-like profiled fibre

Experimentally generated is a 1 THz, 97 fs optical pulse train at 1.55 cm wavelength region based on a comb-like profiled fibre, which consists of 15 pairs of highly nonlinear fibres (HNLFs) and standard singlemode fibres. Such high-repetition rate pulse generation in the 100 fs regime was made possible by the HNLF with high nonlinearity and small dispersion slope.

Compact high repetition rate pseudospark pulse Generator

A pseudospark-based high repetition rate pulse generator, together with a resonant charging power supply is presented. The pulse generator was developed for research applications that include transient plasma ignition. The design incorporates a lumped element Blumlein pulse-forming network that is switched by a commercial pseudospark into an output pulse transformer with a METGLAS core. The Blumlein is charged up to 30 kV by a resonant capacitor charger, based on a fly-back transformer and high-power insulated gate bipolar transistor (IGBT) switch module. The output voltage of the charger is controlled by the on-time of the IGBT. Pulses with duration of 50 ns can be generated at a 2.6-kHz maximum repetition rate. Pulses with amplitude up to 90 kV can be delivered into a 200-/spl Omega/ load.

Surface analysis and grain-boundary segregation measurements using atom-probe techniques

An atom-probe field-ion microscope has been constructed which is capable of giving quantitative analyses of a ∼4 nm diameter region of the specimen surface and also of producing “elemental maps” of areas of the specimen surface with ∼1 nm resolution. The quantitative section of the apparatus uses an energy-compensated time-of-flight spectrometer with high mass-resolution and high sensitivity for trace elements: data collection is rapid, using a high repetition-rate pulse-generator and a solid-state store. The elemental mapping is achieved using a timegated microchannel-plate image-intensifier as the detector of a second time-of-flight spectrometer. The application of this surface instrument to the quantitative analysis of internal interfaces (e.g. grain boundaries) is discussed, with particular reference to the systems Mo/O and Fe/C: for Mo/O the spatial resolution is of order 1 nm, but this is degraded in the iron-carbon system to ∼2 nm by local perturbations of the electric field near the microscopically-rough surface of the specimen.