Resources Contact Us Home
Optical transmitter apparatus

Image Number 16 for United States Patent #7657190.

An optical DQPSK modulator comprises a pair of phase modulators. Each of the pair of the phase modulators is provided with first and second driving signals. The first and second driving signals are amplified by first and second amplifiers, respectively. An RZ intensity modulator generates an optical RZ-DQPSK signal from an optical DQPSK signal output from the optical DQPSK modulator. A photodetector generates a monitor signal from the optical RZ-DQPSK signal. A gain adjuster unit adjusts the gains of the first and second amplifiers so as to minimize the power of the monitor signal.

  Recently Added Patents
Apparatus for electrographic printing or copying
Printed circuit board including electromagnetic bandgap structure
Negative electrode material for non-aqueous electrolyte secondary battery, method for manufacturing negative electrode material for non-aqueous electrolyte secondary battery, non-aqueous elect
Display systems with touch screens
Vehicle and communication monitoring
Electron beam manipulation system and method in X-ray sources
Off-line converter with digital control
  Randomly Featured Patents
Method and apparatus for aerial installation of fiber optic cables
Method and apparatus for determining an ultrasound fluid flow centerline
Method for inhibiting silica and silicate deposition
Multiple environment tank
Optimization system for controlling batch job processing traffic transmitted to a mainframe computer
Headlamp system with selectable beam pattern
Stable chemical compositions containing chromogenic materials, peroxides, and stabilizing chemicals
Fluid transfer device
N-Substituted .alpha.-ketocarboxylic acid amides
Simultaneous data backup in a computer system