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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.

Aerogels are light-weight porous materials that can tolerate the processing steps required for designing and creating an electric circuit such that the aerogel can be utilized as a substrate for device fabrication. Previous studies have shown the biostability and biocompatibility of polyurea crosslinked silica aerogels both in vivo and in vitro and have demonstrated the potential use of aerogels in biomedical applications. In vitro studies have shown that in the presence of an applied electric field neurites regeneration rate was greater on crosslinked silica aerogels than on tissue culture petridish used as a positive control. Currently, epineural suturing and nerve grafting are the gold standards for surgical reconstruction of injured nerves. However, because they rely on passive mechanisms for reapproximating the distal and proximal terminals they often lead to partial or no recovery leaving room for improvement. The present study investigates the feasibility of a wireless aerogel–based electrically-stimulating implant intended for nerve repair applications. Here the authors report on RF coupling between a secondary coil and a primary coil to wirelessly energize an interdigitated electrode array consisting of eleven interlocking fingers, created on a silica aerogel substrate. The coupling strength was tested both in air and in an animal model, as a function of distance and will be reported. This study focuses on in vivo evaluation and feasibility assessment of a novel active 3-D aerogel-based peripheral nerve repair device. The device utilizes induced EMF to establish a current (hence electrical stimulation) in predetermined pathways where nerve stumps will be confined to. Fundamental differences between in vitro and in vivo models necessitate the in vivo approach. The novel inductively-powered electrical stimulation aerogel-based device utilizes previously established 3-D confinement method for immobilization of nerve stumps, taking advantage of the mesoscopic surface roughness, unique to aerogels. The technique is tested on a mechanically strong, lightweight, porous, and biostable aerogel. Lithographic techniques, gold (Au) thin film metallization, and Faraday induction is used for circuit design, development, and activation.

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.

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.

X-ray Charge Coupled Devices (CCDs) have been the workhorse for soft X-ray astronomical instruments for the past quarter century. They provide broad energy response, extremely low electronic read noise, and good energy resolution in soft X-rays. These properties, along with the large arrays and small pixel sizes available with modern-day CCDs, make them a potential candidate for next generation astronomical X-ray missions equipped with large collecting areas, high angular resolutions and wide fields of view, enabling observation of the faint, diffuse and high redshift X-ray universe. However, such high collecting area (about 30 times Chandra) requires these detectors to have an order of magnitude faster readout than current CCDs to avoid saturation and pile up effects. In this context, Stanford University and MIT have initiated the development of fast readout X-ray cameras. As a tool for this development, we have designed a fast readout, low noise electronics board (intended to work at a 5 Megapixel per second data rate) coupled with an STA Archon controller to readout a 512 x 512 CCD (from MIT Lincoln Laboratory). This versatile setup allows us to study a number of parameters and operation conditions including the option for digital shaping. In this paper, we describe the characterization test stand, the concept and development of the readout electronics, and simulation results. We also report the first measurements of read noise, energy resolution and other parameters from this set up. While this is very much a prototype, we plan to use larger, multi-node CCD devices in the future with dedicated ASIC readout systems to enable faster, parallel readout of the CCDs., Comment: To appear in SPIE Astronomical Telescopes + Instrumentation, 2020, Paper No. 11454-80

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.

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.

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

1. When justice isjust iceand soul freezes over,(and when for Black Americanshas justice NOT BEENjust ice?)…When laws are twistedso murdererswalk free—yo, Zimmy, Dubya, Odronea—,no need for any apo...

Arcane is the name for my longer, more structured poems. The Rom Arcane came out of the experience in March 2008 of the pileup of trash in the streets of Naples. This ultimately was connected with attacks on the immigrant and native gypsy camps in Naples and other cities. My poem records the rise in fascism vis-a-vis the destruction of the Left in many places.

"Open Gate" is the first bilingual volume of Haitian Creole poetry published in English. Seven years in the making, this anthology is the result of the dedication of its editors and translators, Paul Laraque, Jack Hirschman and the Haitian poet Boadiba, as well as Max Manigat, one of the first teachers of Creole on the university level who was an invaluable advisor. The editors focus on contemporary Creole poetry that reflects the struggle for human rights in Haiti. The book is divided into three sections: Pioneers of Modern Haitian Creole poetry, beginning with the founder of modern Haitian Creole literature, Felix Morisseu-Leroy (19131998); the flowering of Haitian poetry as represented by the literary movement, "Society of Butterflies," some of whose members were jailed or exiled by the bloody Duvalier dictatorship; and the New Generation featuring primrily those poets in the Diaspora whose work has been published in the last 15 years.

“Become a rag again and the poorest may wave you” Pier Paolo Pasolini: To the Red Flag I put my mouth to your misery, New Orleans, inundated and soaking with death. Here lies: war lies piled so high, this floating prison of a cemetery cries out of rage at the end of its breath. Here, in the last delta, Desire lies on its side, is rolled, and rolled over upon by its own government, and crushed. Summertime is over and the livin’ is dead, and ’round midnight all hopes are looted. No one will come clean of the Katrina of New Orleans in this sinking house of the setting sun. Bodies so Black and so blue from loving what wouldn’t spit on their shoes if they needed a shine. Let alone a dime. Or water. America, you were always scorched earth in our mouths, always a baptism of crap, always a rain of disaster streaming down the panes of our broken eyes. Now our rags are the most torn, our jazz the most blue, our poor the poorest that can be worn in the soul’s thrift shop. Now that all is lost and there’s only nothing to lose...“Long live the courage and the sorrow and the innocence of the poor!” The real flag’s in tatters. Begin to wave it. Jack Hirschman

Cearasar Vallejo: Poemas humanos human poems. Translated by Clayton Eshleman. 326 pp. Grove Press. $8.50 Publisher's Weekly, July 1, 1968