Methods and apparatus for wavelength measurement and tracking using a semiconductor laser amplifier

摘要

This invention demonstrates the methods that use semiconductor laser amplifier (SLA) as a wavelength discriminator, as well as several apparatus designed using these methods. The functions of the invented apparatus include wavelength measurement, wavelength tracking, wavelength comparison, and wavelength stabilization and control of lasers. The key concept for which these methods and apparatus work is the variation of the transparent current of a SLA with the wavelength of an incident light. The transparent current of a SLA can be easily detected from the induced voltage across the diode junction when the incident light is intensity-modulated. The incident wavelength can be accurately determined by measuring the transparent current. These methods and apparatus are expected to be very useful in wavelength display for photonic instruments, wavelength control and wavelength registration for photonic networks, and wavelength stabilization for laser diodes. Since the SLA can be monolithically integrated with semiconductor lasers.