Laser transmitter

Patent · Tue Sep 16 04:00:00 EDT 1986

OSTI ID:5238766

Giles, C R

A laser controller is described for use in a digital transmission system, the controller which consists of: means for applying a bias current to the laser; means for increasing the bias current from a low value below laser threshold to a high value above laser threshold; means for applying a digital data stream to the laser; means for monitoring laser light output power; means for storing monitored light output data (L) as a function of bias current data (I); means for processing the stored data: (i) to derive a second derivative d/sup 2/L/dI/sup 2/ of the L-I curve; (ii) to find first and second peaks in the derivative, the first peak at a bias current I/sub 1/th corresponding to a lowest bias current at which digital '1' but not '0' produces lasing and the second peak corresponding to the lowest bias current I/sub 0/th at which digital '0' produces lasing; and means for setting the bias current at or close to I/sub 0/th.

• Assignee: Northern Telecom, Ltd., Montreal
• Patent Number(s): US 4612671
• OSTI ID: 5238766
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
CONTROL EQUIPMENT
CURRENTS
DATA PROCESSING
DATA TRANSMISSION SYSTEMS
DIAGRAMS
ELECTRIC CONTROLLERS
ELECTRIC CURRENTS
ELECTROMAGNETIC RADIATION
EQUIPMENT
LASER RADIATION
LASERS
MEMORY DEVICES
MONITORING
PERFORMANCE
PROCESSING
RADIATIONS