Low-noise control electronics minimize linewidth, spectral drift and center wavelength jitter. The QCL series ultrastable low-noise quantum cascade laser (QCL) drivers manufactured by Wavelength Electronics Inc. includes the QCL1000 1-A, which offers 0.7-μA rms noise over a 100-kHz bandwidth. Designed as an original equipment manufacturer controller, it can be used in field-deployed systems or on a benchtop, and it can be interfaced to a printed circuit board or via cables. Bandwidth is 2 to 3 MHz, with rise and fall times of 250 and 200 ns. Features include compliance of up to 16 V, constant current mode, onboard set point and limit controls, and dual supply operation at ±24 V. The drivers are used for improving the performance of chemical sensors in the biomedical field.