The quantum cascade laser is a special kind of semiconductor laser, usually emitting in the mid- and long-wave infrared bands. Such a laser operates on laser transitions not between different electronic bands but on intersubband transitions of a semiconductor structure.  Their wide tuning range and fast response time allow for faster …

US Navy  plans to add as many as 32 attack submarines in just the next 15 years. Overall, the addition of attack submarines represents the largest overall platform increase within the Navy’s ambitious plan to grow the fleet to 355 ships. “Battle force inventory reaches 301 in 2020 and 355 in 2034,” …