Back to results
US 6,570,892 B1Granted
Passively mode-locked fiber lasers
AssigneeCalmar Optcom, Inc.
InventorsHong Lin, Katherine Y. Lin
Life of this patent
Estimating the term…
Abstract
A passive mode-locked linear-resonator fiber laser using polarization-maintaining fibers and a saturable absorber to produce ultra short pulses and a long-term reliable operation with reduced maintenance. Such a fiber laser can be configured to produce tunable pulse repetition rate and tunable laser wavelength.
Claims20
A passive mode-locked fiber laser, comprising:
- a pump light source to produce a pump beam at a pump wavelength;
- an optical fiber having at least one doped fiber segment which absorbs light at said pump wavelength to emit light at a laser wavelength within a spectral gain profile is different from said pump wavelength;
- an optical coupler to couple said pump beam from said pump light source into said doped fiber segment;
- first and second reflective elements disposed to form a linear optical resonator that encloses said optical fiber and supports a plurality of longitudinal modes;
- a saturable absorber disposed in said optical resonator and formed of a material that exhibits an intensity-dependent absorption to effectuate a passive mode-locking mechanism to lock said longitudinal modes in phase to produce optical pulses at said laser wavelength;
- a pulse frequency tuning element located in said optical resonator to adjust an optical path length of said optical resonator, during normal mode-locking operation and in response to a control signal, to control a pulse repetition frequency of said optical pulses;
- an optical detector to receive a portion of said optical pulses to produce a detector output;
- and
- a control unit coupled to receive said detector output and to produce said control signal according to information that includes information in said detector output.
6 more elements
A method for generating laser pulses, comprising:
- using two reflective optical elements to form a laser resonator;
- disposing a fiber gain medium in an optical path linking said two reflective optical elements;
- placing a saturable absorber in said optical path linking said two reflective optical elements to lock multiple oscillating resonator modes of said optical resonator to produce optical pulses;
- optically detecting a portion of energy of said optical pulses to measure a pulse repetition rate of said optical pulses;
- and
- during normal mode-locking operation, controlling an optical path length of said optical path between said two reflective elements according to the measured pulse repetition rate to control said pulse repetition rate at a desired pulse repetition rate.
3 more elements
A method, comprising:
- forming an optical resonator by using two reflective elements;
- disposing a fiber gain medium between said two reflective elements to provide an optical gain within a gain spectral range, wherein said fiber gain medium is formed of a polarization-maintaining fiber;
- using a saturable absorber in said resonator to lock multiple resonator modes to produce optical pulses, wherein said satuarable absorber has a slow saturation process with a low saturation intensity and a fast saturation process with a high saturation intensity;
- coupling a pump beam into said resonator at a location between said saturable absorber and said fiber gain medium to direct said pump beam towards said fiber gain medium and to excite said fiber gain medium;
- optically detecting a portion of energy of said optical pulses to measure a pulse repetition rate of said optical pulses;
- and
- during normal mode-locking operation, controlling an optical path length of said optical path between said two reflective elements according to the measured pulse repetition rate to control said pulse repetition rate at a desired pulse repetition rate.
4 more elements
Dependencies are inferred from the claim text.