Anisotropic focusing characteristics of micro-domain structures within crystalline Sr_0.61Ba_0.39Nb₂O₆ : the crystal ball

We report the anisotropic focusing characteristics of a spherically configured region of micro-domains that have been induced within a cubic shaped crystal of Ce:doped Sr0.61Ba0.39Nb2O6. The internal spherical structure focuses extraordinary polarised light, but not ordinary polarised. The spherical region, which is easily observed via scattering, is formed as the crystal cools down, after a repoling cycle through the Curie temperature, with an applied field. Analytic modelling of the thermal gradients that exist within the crystal during cooling reveals a small (< 1°) temperature difference between the central and outside regions. The similarity in shape between these temperature profiles and the observed scattering region suggests a possible mechanism for the growth of this spherical micro-domained structure

Recruiting for the Future: A Realistic Road to a Points-Tested Visa Program in the United States

For over 40 years, lawmakers and academics have been debating whether the United States should adopt a merit-or skills-based approach to labor immigration and a points-based program for selecting foreign workers. Despite having bipartisan support, efforts to adopt such a program thus far have been unsuccessful. This idea is now back at the center of public debate, having been given new life by President Trump. He has called for “merit-based” immigration reforms that would make the United States more effective at attracting the world’s “best and brightest” and make it more competitive in the global marketplace for highly skilled foreign workers. The President’s public embrace of this goal has not been accompanied, however, by any detailed policy proposal or administration-backed bill introduced in Congress. This report capitalizes on this atmosphere of renewed interest by harnessing the current administration’s enthusiasm, providing evidence-based policy guidance, and mapping out a path forward that avoids the policy gridlock and political pitfalls that have beset past efforts to implement a points-based immigration program in the United States. This path forward is presented in the form of a legislative program. The authors recommend that the U.S. create a small pilot program that would allocate 50,000 green cards each year to candidates selected through a novel points-based selection program. Alongside this small pilot, the authors recommend creating a number of administrative supports meant to ensure that this program is effective, flexible, and transparent. Included are guidelines and financial support for U.S. Citizenship and Immigration Services (USCIS) or another executive agency to gather linked long-term data on the employment outcomes of admitted foreign workers; provisions requiring periodic review of the program by relevant congressional committees; and the establishment of a standing advisory board consisting of immigration experts and stakeholders. In designing these proposals, the authors sought to incorporate lessons from both the successes enjoyed by those countries that have already implemented points programs and the failures endured by those involved in past efforts toward comprehensive immigration reform here in the United States. Lessons from the former led the authors to embrace a two-stage selection process and criteria designed to balance both the short-and long-term needs of the U.S. economy. Lessons from the latter led the authors to adopt a more targeted and incremental approach to immigration reform, resulting in a policy proposal that is modest in its size, scope, strategy, and structure. The points-tested visa program laid out in this proposal would be temporary by design, initially authorized for just ten years, and would increase the number of green cards issued each year by only 4%. This program is designed to supplement, not displace, existing employment-related and family-based immigration categories. As such, this proposal does not call for any changes to existing immigration categories. Finally, the proposal embraces a piecemeal and incremental approach to legislative strategy, recommending that the pilot program be introduced in Congress as a standalone bill rather than as part of a comprehensive immigration reform package. For all these reasons, the authors believe that the policy recommendations presented in this report are legislatively achievable and would be programmatically successful

Recruiting for the Future: A Realistic Road to a Points-Tested Visa Program in the United States

For over 40 years, lawmakers and academics have been debating whether the United States should adopt a merit-or skills-based approach to labor immigration and a points-based program for selecting foreign workers. Despite having bipartisan support, efforts to adopt such a program thus far have been unsuccessful. This idea is now back at the center of public debate, having been given new life by President Trump. He has called for “merit-based” immigration reforms that would make the United States more effective at attracting the world’s “best and brightest” and make it more competitive in the global marketplace for highly skilled foreign workers. The President’s public embrace of this goal has not been accompanied, however, by any detailed policy proposal or administration-backed bill introduced in Congress. This report capitalizes on this atmosphere of renewed interest by harnessing the current administration’s enthusiasm, providing evidence-based policy guidance, and mapping out a path forward that avoids the policy gridlock and political pitfalls that have beset past efforts to implement a points-based immigration program in the United States. This path forward is presented in the form of a legislative program. The authors recommend that the U.S. create a small pilot program that would allocate 50,000 green cards each year to candidates selected through a novel points-based selection program. Alongside this small pilot, the authors recommend creating a number of administrative supports meant to ensure that this program is effective, flexible, and transparent. Included are guidelines and financial support for U.S. Citizenship and Immigration Services (USCIS) or another executive agency to gather linked long-term data on the employment outcomes of admitted foreign workers; provisions requiring periodic review of the program by relevant congressional committees; and the establishment of a standing advisory board consisting of immigration experts and stakeholders. In designing these proposals, the authors sought to incorporate lessons from both the successes enjoyed by those countries that have already implemented points programs and the failures endured by those involved in past efforts toward comprehensive immigration reform here in the United States. Lessons from the former led the authors to embrace a two-stage selection process and criteria designed to balance both the short-and long-term needs of the U.S. economy. Lessons from the latter led the authors to adopt a more targeted and incremental approach to immigration reform, resulting in a policy proposal that is modest in its size, scope, strategy, and structure. The points-tested visa program laid out in this proposal would be temporary by design, initially authorized for just ten years, and would increase the number of green cards issued each year by only 4%. This program is designed to supplement, not displace, existing employment-related and family-based immigration categories. As such, this proposal does not call for any changes to existing immigration categories. Finally, the proposal embraces a piecemeal and incremental approach to legislative strategy, recommending that the pilot program be introduced in Congress as a standalone bill rather than as part of a comprehensive immigration reform package. For all these reasons, the authors believe that the policy recommendations presented in this report are legislatively achievable and would be programmatically successful

Nano-droplets deposited in microarrays by femtosecond Ti:sapphire laser-induced forward transfer

The authors present the deposition of nanoscale droplets of Cr using femtosecond Ti:Sapphire Laser-Induced Forward Transfer. Deposits around 300 nm in diameter, significantly smaller than any previously reported, are obtained from a 30 nm thick source film. Deposit size, morphology, and adhesion to a receiver substrate as functions of applied laser fluence are investigated. We show that deposits can be obtained from previously irradiated areas of the source material film with negligible loss of deposition quality, allowing sub-spot size period microarrays to be produced without the need to move the source film

Laser operation of a Tm:Y₂O₃ planar waveguide

We demonstrate the first Tm-doped yttria planar waveguide laser to our knowledge, grown by pulsed laser deposition. A maximum output power of 35 mW at 1.95 µm with 9% slope efficiency was achieved from a 12 µm-thick film grown on a Y3Al5O12 substrate