The 500B series laser diode drivers unveiled by Newport Corp. are available in four models that offer up to 0.1, 0.5, 2.5 or 6.0 A of maximum output. All can be operated in constant-current or constant-light-output mode, and they accept external modulation. They include a USB interface as well as bundled application software and LabView drivers to enable operation through a virtual control panel. The 6-A model can be adjusted with a resolution of 0.12 mA, and patented noise reduction circuitry lowers ripple to <2.5 mA. The modulation bandwidth for the 0.1-A model ranges up to ~800 kHz.