Patent ID: 8855484
Filing Date: 2014-10-07
Classification: H04B

Abstract:
1. A method for controlling optical power and extinction ratio over an entire temperature range, the method being applicable to a fiber-optic transceiver, wherein the fiber-optic transceiver is connected to an electronic device, is configured for generating or receiving a laser beam under control of the electronic device, and comprises a transmitter optical subassembly (TOSA), a laser driver, a controller IC, and a thermal sensor, the TOSA being provided therein with a laser diode but does not requiring require a monitoring photodiode, the laser driver being configured for driving the laser diode under control of the controller IC so as for the laser diode to generate a laser beam to be transmitted outward through an optical fiber, and the thermal sensor being configured for sensing a temperature of the laser diode, the method comprising the steps, performed by the controller IC, of: receiving a relationship between an optical power P(t) and an on-current I(t) of the laser diode over an entire temperature range, receiving operation parameters including bias currents I to determine characteristic constants in the first and second equations by an approximation method and then determine the relationship according to threshold currents I th (t) and corresponding slope efficiencies SE(t) in the entire temperature range obtained from the first and second equations, respectively; wherein the characteristic constants in the first and second equations are I 0 , K 1 , t 1 , S 0 , K s , and t s ; and wherein the operation parameters are obtained, through manually adjusting a bias current I 0 (t n ) and a modulation current I 1 (t n ) of the laser diode at a normal temperature t n so as for the laser diode to generate expected optical powers P 0 (t n ) and P 1 (t n ) at the normal temperature t n , according to a third equation, as follows: and obtaining a current temperature t