Title :
Frequency noise reduction of visible InGaAlP laser diodes by different optical feedback methods
Author :
Simonsen, Harald R.
fDate :
3/1/1993 12:00:00 AM
Abstract :
The emission spectra of several commercial InGaAlP laser diodes operating in the visible range were investigated. Strong relaxation sidebands at frequency spacings up to 2 GHz were observed in the field spectra. By using optical feedback from an external high-finesse resonator, the laser line-width was reduced from a few hundred megahertz to less than one megahertz. However, only a small part of the laser power was found within the narrow bandwidth, whereas most of the power finds itself in relaxation sidebands a few gigahertz apart from the carrier. The frequency noise reduction was investigated by using an external cavity configuration. With a short cavity length the relaxation oscillation sidebands were completely suppressed, and the laser linewidth was reduced to a few megahertz. Additional strong reduction in the laser linewidth to roughly 50 kHz was obtained using a combination of the external cavity laser with optical feedback from an external high-finesse resonator
Keywords :
III-V semiconductors; aluminium compounds; feedback; gallium compounds; indium compounds; laser cavity resonators; semiconductor device noise; semiconductor lasers; spectral line breadth; InGaAlP; emission spectra; external cavity configuration; external high-finesse resonator; field spectra; frequency noise reduction; frequency spacings; laser cavity; laser diodes; laser line-width; laser power; optical feedback methods; oscillation sidebands; relaxation sidebands; semiconductors; short cavity length; visible range; Bandwidth; Costs; Diode lasers; Frequency; Laser feedback; Laser noise; Noise reduction; Optical feedback; Optical resonators; Optical saturation;
Journal_Title :
Quantum Electronics, IEEE Journal of
