Method of generating an ultra-short pulse using a high-frequency ring oscillator

Abstract

The present invention provides a method of generating an ultra-short pulse in a ring oscillator by amplifying a series of wavelength-swept-with time pulses using one or more amplifiers, compressing the amplified wavelength-swept-with time pulses, reducing the compressed pulses to sub-picosecond pulses, stretching the sub-picosecond pulses into wavelength-swept-with time pulses and returning the stretched pulses to the one or more amplifiers.

1 . A method of generating an ultra-short pulse in a ring oscillator, comprising the steps of: 
 amplifying a series of wavelength-swept-with time pulses using one or more amplifiers;    compressing the amplified wavelength-swept-with time pulses;    reducing the compressed pulses to sub-picosecond pulses;    stretching the sub-picosecond pulses into wavelength-swept-with time pulses; and    returning the stretched pulses to the one or more amplifiers.    
   
   
       2 . The method of  claim 1 , wherein the one or more of the one or more amplifiers comprise one or more semiconductor optical amplifiers.  
   
   
       3 . The method of  claim 1 , wherein the compressing is preformed by one or more gratings.  
   
   
       4 . The method of  claim 3 , wherein the one or more gratings comprise a chirped fiber Bragg grating.  
   
   
       5 . The method of  claim 1 , wherein the reducing is preformed by one or more nonlinear optical elements.  
   
   
       6 . The method of  claim 5 , wherein the one or more nonlinear optical elements comprise a carbon nanotube saturable absorber.  
   
   
       7 . The method of  claim 1 , wherein the stretching is preformed by one or more gratings.  
   
   
       8 . The method of  claim 7 , wherein the one or more gratings comprise a chirped fiber Bragg grating.  
   
   
       9 . The method of  claim 1 , wherein the ring oscillator is coupled through an output coupler.  
   
   
       10 . The method of  claim 9 , wherein a portion of each of the amplified pulses are coupled out through the output coupler.  
   
   
       11 . The method of  claim 9 , wherein a portion of each of the compressed pulses are coupled out through the output coupler.  
   
   
       12 . The method of  claim 1 , wherein the oscillator runs at a repetition rate of at least 25 MHz.  
   
   
       13 . The method of  claim 12 , wherein the oscillator further comprises a pulse selector to give a pulse-selector output with a repetition rate of less than one-tenth the oscillator repetition rate.  
   
   
       14 . The method of  claim 13 , further comprising the step of synchronizing the oscillator and the pulse selector, wherein an electrical impulse generator is used to activate a device in the oscillator.  
   
   
       15 . The method of  claim 14 , wherein the electrical impulse generator is used to activate one or more semiconductor optical amplifiers.  
   
   
       16 . The method of  claim 14 , wherein the electrical impulse generator is used to activate an electro-optic modulator to produce a temporal window of net positive pulse amplification within the oscillator.  
   
   
       17 . The method of  claim 1 , wherein the oscillator contains one or more polarization controllers.  
   
   
       18 . The method of  claim 1 , wherein the step of stretching and the step of compressing are preformed by one or more chirped fiber Bragg gratings.  
   
   
       19 . The method of  claim 1 , wherein one or more optical connections between components are made through optical fiber.