Timothy M Ayres

US Patent:

8184670, May 22, 2012

Filed:

Oct 7, 2010

Appl. No.:

12/900453

Inventors:

Ian D. Crawford - Longwood FL, US
John A. Harwick - Sanford FL, US
Timothy M Ayres - Orlando FL, US

Assignee:

Analog Modules, Inc. - Longwood FL

International Classification:

H01S 3/00
H01S 3/13

US Classification:

372 3802, 372 3801, 372 30

Abstract:

In a pulsed laser diode driver an energy storage capacitor is continuously being charged to a supply voltage Vr. When a pulse is initiated, energy stored in the capacitor is delivered to the laser diode load. The capacitor voltage Vd at the end of a pulse is used to control Vr to ensure that Vd is maintained above a minimum voltage Vm required to ensure operation of a current control device (such as FET) just above saturation. Test pulses (such as with attenuated currents or reduced pulsewidth) may be fired to determine an initial optimum value for Vr. After a test pulse, a slightly high estimate for Vr may be used and may be iterated (incremented) down to an optimum value Vm during a firing burst. A digital processor may be used to calculate and store data to optimize the performance. Various embodiments are disclosed.