Back to results
US 6,275,250 B1Granted
Fiber gain medium marking system pumped or seeded by a modulated laser diode source and method of energy control
AssigneeSDL, Inc.
InventorsSteven Sanders, David F. Welch, Stuart MacCormack, Ramon E. Alvarez
Life of this patent
Estimating the term…
Abstract
Double clad fiber gain medium systems particularly adapted for marking indicia on surfaces of articles are disclosed. These systems provide a modulated output from a pump or seed semiconductor laser source to a double clad fiber gain medium which provides an amplified marking output scanned over the article surface with an optical scanner forming a plurality of strokes, the completion of which results in the indicia.
Claims41
A fiber gain medium system comprising:
- a marking laser comprising double clad fiber having a doped core surrounded by an inner pump cladding of a prescribed cross-sectional geometry and providing a marking output;
- a plurality of semiconductor laser sources for pumping said double clad fiber and comprising a plurality of discrete, separately mounted laser diodes and modulated to provide a modulated output from said marking laser the output of said discrete laser diodes combined together;
- said combined output coupled to said double clad fiber inner pump cladding so that brightness conservation is achieved;
- an optical scanner coupled to receive the marking output from said marking laser as modulated by said discrete laser diodes and scan the marking output over a surface of an article to be marked;
- and
- a controller to control the operation of said optical scanner in synchronism with modulation of said discrete laser diodes to initiate said modulated marking output in multiple directions via said optical scanner to form strokes comprising discernable indicia on the article surface.
3 more elements
A fiber gain medium marking system comprising:
- a double clad fiber having a doped core surrounded by an inner pump cladding and providing an optical output for marking at wavelengths in excess of 1,000 μm due to the inherent gain bandwidth of said fiber;
- a semiconductor laser source for pumping or seeding said double clad fiber;
- an optical scanner coupled to receive the optical output from said double clad fiber for scanning said output in at least one dimension over a surface of an article to be marked with said output;
- said article comprising a silicon surface with optimum absorption range at wavelengths below about 1,000 μm;
- and
- a frequency conversion device provided in optical alignment between the marking output of said double clad fiber and said optical scanner for frequency doubling of said double clad fiber marking output to provide a wavelength below about 1,000 μm within the optimum absorptive range of the silicon surface.
3 more elements
A fiber gain medium system comprising:
- a marking laser comprising double clad fiber having a doped core surrounded by an inner pump cladding and providing a marking output;
- a semiconductor laser source for pumping or seeding said marking laser;
- a drive circuit for providing a modulated output for controlling a current level provided to said semiconductor laser source and, correspondingly, the optical output intensity level provided to said marking laser;
- an optical scanner coupled to receive the marking output from said marking laser as modulated by said semiconductor laser source and scan said marking output over a surface of an article to be marked;
- a controller to control the operation of said optical scanner in synchronism with modulation of said semiconductor laser source to provide a modulated marking output from said scanner scanned in multiple directions to form strokes comprising discernable indicia on the article surface;
- and
- a circuit control to provide an initially higher peak value in the initiation of the modulated marking output prior to a subsequent steady-state condition to produce a faster initial ON-time response between an application of the modulation of the semiconductor laser source and the modulated output of said marking laser.
4 more elements
A method of energy control in a fiber gain medium comprising the steps of:
- providing a drive circuit for producing a modulated output to control the light output provided from a laser diode source pumping or seeding a fiber marking gain medium;
- modulating the diode laser source to provide a corresponding modulated marking output;
- scanning the modulated marking output over a surface of an article to be marked in multiple directions to form strokes comprising discernable indicia on the article surface;
- controlling the operation of the optical scanner in synchronism with modulation of the laser diode source to provide a modulated marking output from the scanner with scanning thereof in multiple directions to form strokes comprising discernable indicia on the article surface;
- controlling the modulated marking output to have an ON-time period with an initial peak value at the beginning of the ON-time period higher than a subsequent steady-state condition of the period;
- and
- reducing the rise time to the initial peak value at the beginning of an ON-time period of the modulated marking output prior to clamping the same to its subsequent steady-state condition reducing the response time between initiation of the modulated marking output and the onset of the laser diode modulated output.
4 more elements
A fiber gain medium system comprising:
- a gain medium comprising a fiber having a doped core and providing an optical marking output;
- a plurality of semiconductor laser sources for pumping said gain and comprising a plurality of discrete, separately mounted laser diodes and modulated to provide a modulated output from said gain medium;
- an optical scanner coupled to receive the marking output from said marking laser as modulated by said discrete laser diodes and scan the marking output over a surface of an article to be marked;
- and
- a controller to control the operation of said optical scanner synchronously with combined modulation of said discrete laser diodes to initiate said modulated marking output in multiple directions via said optical scanner to form strokes comprising discernable indicia on the article surface;
- said discrete laser diodes independently modulated relative to one another to achieve different marking contrasts for said discernable indicia.
3 more elements
Dependencies are inferred from the claim text.