Researchers at Sandia National Laboratories have successfully integrated a terahertz quantum-cascade laser and diode mixer into a monolithic solid-state transceiver, taking the first steps toward reducing the size and enhancing the functionality of devices in the terahertz frequency spectrum. Putting the detector and laser on the same chip makes for a compact receiver and doesn’t require the precision alignment of optical components currently needed to couple the laser to the detector. Sandia points out that terahertz radiation is of interest because some frequencies can be used to see through certain materials for various applications ranging from dental or skin cancer imaging to security such as whole body imaging and possibly even to identify chemical or biological weapons and narcotics.