Title :
Phase-encoded optical sampling for analog-to-digital converters
Author :
Twichell, J.C. ; Helkey, R.
Author_Institution :
Lincoln Lab., MIT, Lexington, MA, USA
Abstract :
A high-speed optical sampling system for electrical signals has been developed using a gain-switched diode laser and a dual-output Mach-Zehnder interferometer. The optical phase shift between the branches of the interferometer is highly linear in the applied electrical signal. The phase shift is encoded in the two outputs of the interferometer and is recovered through digital signal processing. Analog-to-digital (A/D) conversion with 78-dB spur-free dynamic range is demonstrated. Our phase-encoded sampling technique allows high-resolution (12-bit) conversion with high linearity at practical laser power levels.
Keywords :
Mach-Zehnder interferometers; analogue-digital conversion; electro-optical modulation; light interferometry; phase coding; semiconductor lasers; signal processing; analog-to-digital conversion; analog-to-digital converters; applied electrical signal; digital signal processing; dual-output Mach-Zehnder interferometer; electrical signals; gain-switched diode laser; high linearity; high-resolution 12-bit conversion; high-speed optical sampling system; laser power levels; optical phase recovery; optical phase shift; phase shift encoding; phase-encoded optical sampling; phase-encoded sampling technique; spur-free dynamic range; Analog-digital conversion; Digital signal processing; Diode lasers; Dynamic range; High speed optical techniques; Optical interferometry; Optical signal processing; Phase shifting interferometry; Sampling methods; Signal sampling;
Journal_Title :
Photonics Technology Letters, IEEE
