High speed data link and transmitter in the mid-infrared wavelength range

Abstract

A mid-infrared transmitter for providing a light signal in a free-space communication system includes an arrangement for producing electromagnetic radiation having a certain wavelength in a mid-infrared wavelength range. The mid-infrared transmitter further includes an arrangement for modulating the electromagnetic radiation so as to provide a train of light pulses having the certain wavelength as the light signal.

What is claimed is:  
     
         1 . A mid-infrared transmitter for providing a light signal in a free-space communication system, said transmitter comprising: 
 means for producing electromagnetic radiation, said electromagnetic radiation having a certain wavelength in a mid-infrared wavelength range; and    means for modulating said electromagnetic radiation so as to provide a train of light pulses having said certain wavelength as said light signal.    
     
     
         2 . The mid-infrared transmitter of  claim 1  wherein said electromagnetic radiation producing means includes a laser diode.  
     
     
         3 . The mid-infrared transmitter of  claim 2  wherein said laser diode is a quantum cascade laser.  
     
     
         4 . The mid-infrared transmitter of  claim 2  wherein said laser diode is a germanium laser.  
     
     
         5 . The mid-infrared transmitter of  claim 2  wherein said laser diode is an antimonide laser.  
     
     
         6 . The mid-infrared transmitter of  claim 1  wherein said mid-infrared wavelength range includes wavelengths between 3 and 5 microns.  
     
     
         7 . The mid-infrared transmitter of  claim 1  wherein said mid-infrared wavelength range includes wavelengths between 8 and 12 microns.  
     
     
         8 . The mid-infrared transmitter of  claim 1  wherein said modulating means is configured to modulate said electromagnetic radiation after said electromagnetic radiation has been produced by said electromagnetic radiation producing means so as to produce said train of light pulses.  
     
     
         9 . The mid-infrared transmitter of  claim 1  wherein said electromagnetic radiation producing means is configured to accept an electrical signal, and wherein said modulating means includes means for providing said electrical signal so as to provide said train of light pulses.  
     
     
         10 . The mid-infrared transmitter of  claim 9  wherein said input signal is a driving voltage, and wherein said modulating means is configured to modulate said driving voltage and to supply said driving voltage, so modulated, to said electromagnetic radiation producing means so as to provide said train of light pulses.  
     
     
         11 . The mid-infrared transmitter of  claim 9  wherein said input signal is a driving current, and wherein said modulating means id configured to modulate said driving current and to supply said driving current, so modulated, to said electromagnetic radiation producing means so as to provide said train of light pulses.  
     
     
         12 . The mid-infrared transmitter of  claim 1  wherein said electromagnetic radiation producing means is tunable such that said certain wavelength of said electromagnetic radiation is consequently tunable over a range of wavelengths within said mid-infrared wavelength range.  
     
     
         13 . The mid-infrared transmitter of  claim 1  further comprising: 
 a plurality of additional means for producing a plurality of additional electromagnetic radiation, each of said plurality of additional electromagnetic radiation having a distinct wavelength in said mid-infrared wavelength range; and  
 a plurality of additional means, each cooperating with at least one of said additional electromagnetic radiation producing means, for providing a plurality of trains of light pulses as said light signal, each of said plurality of trains of light pulses having said distinct wavelength.  
 
     
     
         14 . The mid-infrared transmitter of  claim 1  further comprising means for directing said train of light pulses toward a particular location.  
     
     
         15 . The mid-infrared transmitter of  claim 14  wherein said directing means is adjustable to compensate for possible distortion in said light pulses, said distortion potentially being produced during transmission of the light pulses toward said particular location.  
     
     
         16 . The mid-infrared transmitter of  claim 15  wherein said directing means includes a conformable mirror.  
     
     
         17 . A mid-infrared free space data link comprising: 
 a transmitter arrangement producing a transmitter output, said transmitting arrangement including    a source of light having a certain wavelength in a mid-infrared wavelength range,    a modulator arrangement for modulating said light so as to provide a train of light pulses having said certain wavelength as said transmitter output;    a directing arrangement for directing said transmitter output to a particular location; and    at said particular location, a receiving arrangement configured for receiving said transmitter output.    
     
     
         18 . The mid-infrared free space data link of  claim 17  wherein said directing arrangement includes a conformable mirror.  
     
     
         19 . The mid-infrared free space data link of  claim 17  wherein said mid-infrared wavelength range includes wavelengths between 3 and 5 microns.  
     
     
         20 . The mid-infrared free space data link of  claim 17  wherein said mid-infrared wavelength range includes wavelengths between 8 and 12 microns.  
     
     
         21 . The mid-infrared free space data link of  claim 17  wherein said source includes a laser diode.  
     
     
         22 . The mid-infrared free space data link of  claim 21  wherein said laser diode is a quantum cascade laser.  
     
     
         23 . The mid-infrared free space data link of  claim 21  wherein said laser diode is a germanium laser.  
     
     
         24 . The mid-infrared free space data link of  claim 21  wherein said laser diode is an antimonide laser.  
     
     
         25 . The mid-infrared free space data link of  claim 17  wherein said modulator arrangement is configured to modulate said light after said light has been produced by said source so as to produce said train of light pulses.  
     
     
         26 . The mid-infrared free space data link of  claim 17  wherein said source is configured to accept an input signal, and wherein said modulator arrangement is configured to modulate said input signal so as to provide said train of light pulses.  
     
     
         27 . The mid-infrared free space data link of  claim 26  wherein said input signal is a driving voltage and wherein said modulator arrangement is configured to modulate said driving voltage so as to provide said train of light pulses.  
     
     
         28 . The mid-infrared free space data link of  claim 26  wherein said input signal is an input current and wherein said modulator arrangement is configured to modulate said input current so as to provide said train of light pulses  
     
     
         29 . The mid-infrared free space data link of  claim 17  wherein said source is tunable such that said certain wavelength of said light is consequently tunable over a range of wavelengths within said mid-infrared range.  
     
     
         30 . The mid-infrared free space data link of  claim 17  wherein said receiver further includes 
 a plurality of additional sources of additional light, each of said plurality of additional light having a distinct wavelength in said mid-infrared wavelength range; and  
 a plurality of additional arrangements, each cooperating with at least one of said additional sources, for providing a plurality of trains of light pulses as said transmitter output, each of said plurality of trains of light pulses having said distinct wavelength.  
 
     
     
         31 . A method for providing a mid-infrared free space data link, said method comprising: 
 transmitting a signal containing data, said transmitting step including 
 generating light having a certain wavelength in a mid-infrared wavelength range,  
 modulating light so as to provide a train of light pulses having said certain wavelength as said signal;  
 directing said signal toward a particular location; and  
 at said particular location, receiving said signal.  
   
     
     
         32 . The method of  claim 31  wherein said directing step includes adjusting said directing means to compensate for possible distortion in said signal, said distortion being potentially produced during transmission of said signal toward said particular location.  
     
     
         33 . The method of  claim 31  wherein said adjusting step includes using a conformable mirror.  
     
     
         34 . A method for providing a mid-infrared free space data link for communicating a data signal, said method comprising: 
 providing an input signal,    generating, in response to said input signal, light having a certain wavelength in a mid-infrared wavelength range, wherein said step of providing said input signal includes configuring said input signal so as to provide a train of light pulses having said certain wavelength as said signal;    directing said data signal toward a particular location; and    at said particular location, receiving said signal.    
     
     
         35 . The method of  claim 34  wherein said step of providing said input signal includes the step of supplying an input voltage as said input signal.  
     
     
         36 . The method of  claim 34  wherein said step of providing said input signal includes the step of supplying an input current as said input signal.