title: Even-order harmonic cancellation for off-quadrature biased Mach-Zehnder modulator with improved RF metrics using dual wavelength inputs and dual outputs.
abstract: We present a technique using a dual-output Mach-Zehnder modulator (MZM) with two wavelength inputs, one operating at low-bias and the other operating at high-bias, in order to cancel unwanted even-order harmonics in analog optical links. By using a dual-output MZM, this technique allows for two suppressed optical carriers to be transmitted to the receiver. Combined with optical amplification and balanced differential detection, the RF power of the fundamental is increased by 2 dB while the even-order harmonic is reduced by 47 dB, simultaneously. The RF noise figure and third-order spurious-free dynamic range (SFDR(3)) are improved by 5.4 dB and 3.6 dB, respectively. Using a wavelength sensitive, low V(pi) MZM allows the two wavelengths to be within 5.5 nm of each other for a frequency band from 10 MHz to 100 MHz and 10 nm for 1 GHz.
authors.affiliation: U S Naval Research Laboratory, 4555 Overlook Ave SW, Washington, D C 20375, USA. pdevgan@ccs.nrl.navy.mil
authors.forename: Preetpaul S
authors.initials: PS
authors.lastname: Devgan
authors.forename: John F
authors.initials: JF
authors.lastname: Diehl
authors.forename: Vincent J
authors.initials: VJ
authors.lastname: Urick
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Sunderman
authors.forename: Keith J
authors.initials: KJ
authors.lastname: Williams
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D008872:Microwaves; D055096:Optical Devices; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013685:Telecommunications / Q000295:instrumentation*