Search

A full start-to-end (S2E) software model of a laser system – including oscillator, amplifier, stretcher/compressor, pulse shaper, and non-linear conversion – can be essential in choosing the hardware design and establishing limitations on what can be accomplished given a specific hardware setup. Furthermore, such S2E models can even allow one to reverse engineer a laser system should it be necessary for characterization. Here, we present a generalized S2E model of a photoinjector laser system, currently targeted for X-ray Free-Electron Lasers but which can readily be adapted to any broadly defined laser system.

Ultralow phase-noise mode-locked lasers are crucial for real-world applications. We present two accomplishments: (1) short-term FF CEP stabilization of a SESAM mode-locked Er:Yb:glass laser at 1.55 um with timing jitter below 3 as (1-3 MHz) and (2) a hybrid solution adding a FB technique addressing slowly varying sources of interference to the FF system that demonstrates 75 hours of stabilization with a minimally detrimental effect amounting to a timing jitter of 11 as.

The structuring of laser light with non-diffracting vector distributions, optical vortices, or high angular momentum are being increasing exploited. We present a system for the synthesis of these arbitrary intensity and phase profiles through a number of carrier-envelope-phase stabilized coherent frequency and spatial combs. Adjusting the differences between adjacent combs allows synthesis of a combined field which can be structured, directed, and improved in the presence of propagation noise. Additionally, we present a method for the optimization of such systems in free space with a Fourier optics based genetic algorithm that converges to

We present a novel nonlinear laser shaping technique to increase X-ray Free Electron Laser brightness and preliminary results estimate an improvement of 25% in emittance relative to the standard configuration of the LCLS-II.

Hardware-based machine learning for photoinjector manipulation is a promising solution for real-time adaptive electron-beam manipulation. We present preliminary studies towards this goal including simulations of the optical system and early machine learning results.

We present a method to control the temporal profile of the LCLS-II X-ray free-electron laser by selectively heating parts of the electron beam with a spectrally shaped laser for fast pulse shaping.

In the context of diffractive optics, phase retrieval is a heavily investigated process of recreating an entire complex electric field from partial amplitude-only information through iterative algorithms. However, existing methods can fall into local minima during reconstructions or struggle to recover unusual and novel electric field distributions. We present a numerical method based on a global-optimization genetic algorithm that reconstructs non-trivial electric field distributions from single diffracted intensity distributions. Diffraction and propagation of the optical fields over arbitrary distances is modeled through implementation of the angular spectrum technique. Additionally, a coherently-locked laser array system is used as an experimental case-study demonstrating 0.09π phase reconstruction accuracy of initial laser parameters from single intensity images.

The structural versatility of light underpins an outstanding collection of optical phenomena where both geometrical and topological states of light can dictate how matter will respond or display. Light possesses multiple degrees of freedom such as amplitude, and linear, spin angular, and orbital angular momenta, but the ability to adaptively engineer the spatio-temporal distribution of all these characteristics is primarily curtailed by technologies used to impose any desired structure to light. We demonstrate a laser architecture based on coherent beam combination offering integrated spatio-temporal field control and programmability, thereby presenting unique opportunities for generating light by design to exploit its topology.

Microbunching instability (MBI) driven by beam collective effects is known to be detrimental to high-brightness storage rings, linacs, and free-electron lasers (FELs). One known way to suppress this instability is to induce a small amount of energy spread to an electron beam by a laser heater. The distribution of the induced energy spread greatly affects MBI suppression and can be controlled by shaping the transverse profile of the heater laser. Here, we present the first experimental demonstration of effective MBI suppression using a LG_{01} transverse laser mode and compare the improved results with respect to traditional Gaussian transverse laser mode at the Linac Coherent Light Source. The effects on MBI suppression are characterized by multiple downstream measurements, including longitudinal phase space analysis and coherent radiation spectroscopy. We also discuss the role of LG_{01} shaping in soft x-ray self-seeded FEL emission, one of the most advanced operation modes of a FEL for which controlled suppression of MBI is critical.

We present carrier-envelope phase stabilization of an Er:Yb:glass laser at 1.55 pm via the feed-forward method with 2.9 as (1 Hz - 3 MHz) timing jitter and continuous stabilization over 24 hours.

we will review recent advances exploiting laser-particle interactions to enhance the performance of accelerators and X-ray free electron lasers and their applications in ultrafast science.

we examine an integrated laser architecture offering adaptive spatio-temporal field distribution and topology, including control over its amplitude, and linear, spin angular, and orbital angular momenta to exploit its topology.

We present the new drive laser system for the photo-injector of the LCLS-II XFEL at SLAC, including the first commissioning results and challenges encountered due to high power, high repetition rate ultraviolet laser operation.

Controlling the CEP in mode-locked lasers over long timescales is crucial for real-world applications. We present a hybrid stabilization system in an Er: Yb:glass mode-locked laser with 75 hours of stabilization and IPN below 14 mrad.

we will review spatio-temporally tailored laser-electron interactions that enhance linear accelerator and free electron laser brightness to advance ultrafast X-ray spectroscopies.

Controlling the CEP in mode-locked lasers over long timescales is crucial for real-world applications. We present a hybrid stabilization system in an Er:Yb:glass mode-locked laser with 75 hours of stabilization and IPN below 14 mrad.

We present a method for the optimization of complex laser systems and laser shaping tools using a genetic algorithm utilizing accurate simulation based on Fourier optics.

We present a carrier envelope phase (CEP) stable system capable of arbitrary intensity, phase, and spin angular momentum distributions based on the principles of free-space coherent synthesis.

we present the synthesis of ultrashort laser bullets with real-time adaptive and programmable field topology, including field amplitude, and linear, spin angular, and orbital angular momenta.

We present a generalized light source architecture offering dynamic topological control with a broad ensemble of complex states of light to drive, probe or interact with quantum and nonlinear systems..

We present a method for reconstruction of intensity profiles, and the related near field parameters, generated by coherent synthesis systems using globally optimizing genetic algorithm based on Fourier propagation methods.

Few-cycle pulsed laser technology highlights the need for control and stabilization of the carrier-envelope phase (CEP) for applications requiring shot-to-shot timing and phase consistency. This general requirement has been achieved successfully in a number of free space and fiber lasers via feedback and feed-forward methods. Expanding upon existing results, we demonstrate CEP stabilization through the feed-forward method applied to a SESAM mode-locked Er:Yb:glass laser at 1.55 um with a measured ultralow timing jitter of 2.9 as (1 Hz - 3 MHz) and long-term stabilization over a duration of eight hours. Single-digit attosecond stabilization at telecom wavelengths opens a new direction in applications requiring ultra-stable frequency and time precision such as high-resolution spectroscopy and fiber timing networks., Comment: 4 pages, 4 figures, submitted to Optics Letters

Controlling the carrier envelope phase (CEP) in mode-locked lasers over practically long timescales is crucial for real-world applications in ultrafast optics and precision metrology. We present a hybrid solution that combines a feed-forward technique to stabilize the phase offset in fast timescales and a feedback technique that addresses slowly varying sources of interference and locking bandwidth limitations associated with gain media with long upper-state lifetimes. We experimentally realize the hybrid stabilization system in an Er:Yb:glass mode-locked laser and demonstrate 75 hours of stabilization with integrated phase noise of 14 mrad (1 Hz to 3 MHz), corresponding to around 11 as of carrier to envelope jitter. Additionally, we examine the impact of environmental factors, such as humidity and pressure, on the long-term stability and performance of the system., 11 pages, 6 figures, 1 table; to be published in Optics Express; revisions include adjustment of some citations, additions to section 2, and added information in table 1

we present a laser architecture that synthesizes arbitrary 4D-structured femtosecond light with full polarization vector, transverse and longitudinal intensity, and wavefront control as a novel tool to probe and control matter.

We report on a direct diode-pumped Ti:sapphire ultrafast regenerative amplifier laser system producing multi-μJ energies with a repetition rate from 50 to 250 kHz. By combining cryogenic cooling of Ti:sapphire with high brightness fiber-coupled 450nm laser diodes, we for the first time demonstrate a power-scalable CW-pumped architecture that can be directly applied to demanding ultrafast applications such as coherent high-harmonic EUV generation without any complex post-amplification pulse compression. Initial results promise a new era for Ti:sapphire amplifiers not only for ultrafast laser applications, but also for tunable CW sources. We discuss the unique challenges to implementation, as well as the solutions to these challenges.