title: A sensitive and high dynamic range cw laser power meter.
abstract: We report the design of a cost effective, highly sensitive cw laser power meter with a large dynamic range based on a photodiode. The power meter consists of a photodiode, a current to voltage converter circuit, an offset balancing circuit, a microcontroller, an analog to digital converter, reed relays, and an alphanumeric liquid crystal display. The power meter can record absolute laser power levels as low as 1 pW. The dynamic range measured with a cw laser at a wavelength of 532 nm is 8x10(10). The high sensitivity and large dynamic range are achieved by the implementation of an analog background balancing circuit and autoranging.
authors.affiliation: Laser Physics Applications Division, Raja Ramanna Centre for Advanced Technology, Indore 452013, India. skrish@rrcat.gov.in
authors.forename: S
authors.initials: S
authors.lastname: Krishnan
authors.forename: K S
authors.initials: KS
authors.lastname: Bindra
authors.forename: S M
authors.initials: SM
authors.lastname: Oak