Methods, apparatus, and systems with semiconductor laser packaging for high modulation bandwidth

Abstract

Semiconductor packaging methods, systems and apparatus for semiconductor lasers to achieve high modulation bandwidth. Systems, methods and apparatus for minimizing the inductance of wire bond interconnects and impedance matching in a semiconductor laser package. Systems, methods and apparatus for monitoring a photocurrent in order to provide automatic power control (APC) of a semiconductor laser.

1 - 50 . (canceled)  
   
   
       51 . A packaged semiconductor laser transmitter for high modulation bandwidth, the packaged semiconductor laser transmitter comprising: 
 a thin-outline device package including a thin-outline header having a feedthrough pin with a first impedance;    a semiconductor laser mounted within the thin-outline device package, the semiconductor laser having an electrical contact with a second impedance;    an impedance-controlled circuit coupled between the feedthrough pin of the thin-outline header and the electrical contact of the semiconductor laser, the impedance-controlled circuit having a third impedance at one contact point and a fourth impedance at another contact point; and    wherein the third impedance of the impedance-controlled circuit to match the first impedance of the feedthrough pin of the thin-outline header, the fourth impedance of the impedance-controlled circuit to match the second impedance of the electrical contact of the semiconductor laser, and the impedance-controlled circuit to provide a low impedance in a first interconnect between the semiconductor laser and the impedance-controlled circuit and a low impedance in a second interconnect between the feedthrough pin of the thin-outline header and the impedance-controlled circuit for high modulation bandwidth.    
   
   
       52 . The packaged semiconductor laser transmitter of  claim 51 , wherein 
 the first impedance of the feedthrough pin of the thin-outline header differs from the second impedance of the electrical contact of the semiconductor laser, and    the impedance-controlled circuit compensates for the difference between the first impedance and the second impedance.    
   
   
       53 . The packaged semiconductor laser transmitter of  claim 51 , wherein 
 the first impedance of the feedthrough pin of the thin-outline header matches the second impedance of the electrical contact of the semiconductor laser, and the third impedance and the fourth impedance of the impedance-controlled circuit matches the first impedance and the second impedance, respectively.    
   
   
       54 . The packaged semiconductor laser transmitter of  claim 53 , wherein 
 the second impedance of the electrical contact of the semiconductor laser is fifty ohms over a given frequency range and the first impedance of the feedthrough pin of the thin-outline header is fifty ohms over the given frequency range, and    the third impedance and the fourth impedance of the impedance-controlled circuit are fifty ohms over the given frequency range.    
   
   
       55 . The packaged semiconductor laser transmitter of  claim 51  further comprising: 
 a window can coupled to the thin-outline header, the window can having a window to allow a first portion of a laser beam from the semiconductor laser to pass through and out from the packaged semiconductor laser transmitter.    
   
   
       56 . The packaged semiconductor laser transmitter of  claim 55  further comprising: 
 a photodetector mounted within the thin-outline device package, and    wherein the window can is a slanted window can having a window to redirect a second portion of the laser beam from the semiconductor laser to the photodetector.    
   
   
       57 . The packaged semiconductor laser transmitter of  claim 56 , wherein 
 the photodetector mounted within the thin-outline device package to receive the second portion of the laser beam to facilitate automatic power control of the semiconductor laser.    
   
   
       58 . The packaged semiconductor laser transmitter of  claim 51 , wherein 
 the impedance-controlled circuit includes at least one impedance control line to provide the third impedance at the one contact point and the fourth impedance at the another contact point.    
   
   
       59 . The packaged semiconductor laser transmitter of  claim 58 , wherein 
 the impedance-controlled circuit further includes a printed circuit board and the at least one impedance control line is on top of the printed circuit board.    
   
   
       60 . The packaged semiconductor laser transmitter of  claim 51 , wherein 
 the first interconnect and the second interconnect are a first bond wire and a second bond wire, respectively, and    the semiconductor laser, the impedance-controlled circuit, and the feedthrough pin of the thin-outline header are positioned with respect to each other within the thin-outline device package to minimize a length of the first bond wire and a length of the second bond wire.    
   
   
       61 . The packaged semiconductor laser transmitter of  claim 58 , wherein 
 the first interconnect and the second interconnect are a first bond wire and a second bond wire, respectively,    the semiconductor laser, the impedance-controlled circuit, and the feedthrough pin of the thin-outline header are positioned with respect to each other within the thin-outline device package to minimize a length of the first bond wire and a length of the second bond wire, and    with respect to the thin-outline header, a height of a top surface of the semiconductor laser, a height of a top surface of the at least one control line, and a height of a top surface of the feedthrough pin of the thin-outline header are substantially equal to further minimize the length of the first bond wire and the length of the second bond wire.    
   
   
       62 . The packaged semiconductor laser transmitter of  claim 60 , wherein 
 the first bond wire is a first plurality of bond wires and the second bond wire is a second plurality of bond wires, respectively, to reduce inductance in the first interconnect and the second interconnect, respectively.    
   
   
       63 . The packaged semiconductor laser transmitter of  claim 60 , wherein 
 the first bond wire and the second bond wire are thick bond wires to reduce inductance in the first interconnect and the second interconnect, respectively.    
   
   
       64 . The packaged semiconductor laser transmitter of  claim 60 , wherein 
 the first bond wire and the second bond wire are ribbon bond wires to reduce inductance in the first interconnect and the second interconnect, respectively.    
   
   
       65 . The packaged semiconductor laser transmitter of  claim 51 , wherein 
 the semiconductor laser is a vertical cavity surface emitting laser.    
   
   
       66 . The packaged semiconductor laser transmitter of  claim 51  further comprising: 
 a submount mounted within the thin-outline device package and coupled between a bottom surface of the semiconductor laser and a top surface of the thin-outline header.    
   
   
       67 . The packaged semiconductor laser transmitter of  claim 66 , wherein 
 the submount has one or more vias to conductively couple the bottom surface of the semiconductor laser to the thin-outline header.    
   
   
       68 . The packaged semiconductor laser transmitter of  claim 66  further comprising: 
 a conductive block mounted within the thin-outline device package, a bottom surface of the conductive block conductively coupled to the thin-outline header, a top surface of the conductive block conductively coupled to a top surface of the submount, the conductive block to minimize a total number of bond wires and to lower inductance.    
   
   
       69 . A method of packaging a semiconductor laser to provide high modulation bandwidth, the method comprising: 
 matching a feedthrough impedance of a first pin of a device package to an input impedance of a semiconductor laser at an input contact; and    minimizing an inductance in an interconnect between the first pin and the input contact of the semiconductor laser.    
   
   
       70 . The method of  claim 69 , wherein 
 the minimizing of the inductance in the interconnect includes 
 minimizing a length of a first bondwire coupled between the first pin and the input contact of the semiconductor laser.  
   
   
   
       71 . The method of  claim 70 , wherein 
 the minimizing of the inductance in the interconnect further includes 
 maximizing a cross sectional area of the first bondwire coupled between the first pin and the input contact of the semiconductor laser.  
   
   
   
       72 . The method of  claim 69 , wherein 
 the minimizing of the inductance in the interconnect includes 
 minimizing a distance between the first pin and the input contact of the semiconductor laser.  
   
   
   
       73 . The method of  claim 72 , wherein 
 the minimizing of the inductance in the interconnect further includes 
 providing a plurality of bondwires coupled between the first pin and the input contact of the semiconductor laser.  
   
   
   
       74 . The method of  claim 72 , wherein 
 the minimizing of the inductance in the interconnect further includes 
 leveling a surface of the input contact of the semiconductor laser with a top surface of a post of the first pin.  
   
   
   
       75 . The method of  claim 72 , wherein 
 the minimizing of the inductance in the interconnect further includes 
 mounting the semiconductor laser within a device package to level a surface of the input contact of the semiconductor laser with a top surface of a post of the first pin.  
   
   
   
       76 . The method of  claim 69  further comprising: 
 matching a feedthrough impedance of a second pin of the device package to an input impedance of a photodetector at an input contact.    
   
   
       77 . The method of  claim 76  further comprising: 
 minimizing an inductance in an interconnect between the second pin and the input contact of the photodetector.    
   
   
       78 . The method of  claim 69  further comprising: 
 redirecting a portion of a laser beam from the semiconductor laser to a photodetector, and    monitoring the photocurrent generated by the photodetector in response to the redirected portion of the laser beam to obtain a measure of an optical power output in the portion of the laser beam exiting from the device package.    
   
   
       79 . The method of  claim 78  further comprising: 
 automatically controlling the optical power output from the device package in response to the monitoring of the photocurrent.    
   
   
       80 . A transmitter optical subassembly comprising: 
 a fiber optic connector having a port;    a packaged transmitter for high modulation bandwidth, the packaged transmitter having a light emitting end mounted into the port of the fiber optic connector, the packaged transmitter including 
 a thin-outline device package including a thin-outline header having a feedthrough pin with a feedthrough impedance;  
 a semiconductor laser mounted within the thin-outline device package to provide a low impedance in a first interconnect coupled between the feedthrough pin and an electrical contact of the semiconductor laser, the electrical contact of the semiconductor laser having an input impedance; and  
 wherein the feedthrough impedance of the feedthrough pin of the thin-outline header to substantially match the input impedance of the electrical contact of the semiconductor laser.  
   
   
   
       81 . The transmitter optical subassembly of  claim 80  further comprising: 
 a lens mounted into the port of the fiber optic connector in front of the light emitting end of the packaged transmitter, the lens to collimate light exiting from the packaged transmitter into a fiber optic cable.    
   
   
       82 . The transmitter optical subassembly of  claim 80 , wherein 
 the packaged transmitter further includes 
 a window can coupled to the thin-outline header, the window can having a window to allow a first portion of a laser beam from the semiconductor laser to pass through and exit the packaged transmitter at the light emitting end.  
   
   
   
       83 . The transmitter optical subassembly of  claim 82 , wherein 
 the packaged transmitter further includes 
 a photodetector mounted within the thin-outline device package, and  
 wherein the window can is a slanted window can having a window to redirect a second portion of the laser beam from the semiconductor laser to the photodetector.  
   
   
   
       84 . The transmitter optical subassembly of  claim 83 , wherein 
 the photodetector mounted within the thin-outline device package to receive the second portion of the laser beam to facilitate automatic power control of the semiconductor laser.    
   
   
       85 . A fiber optic module comprising: 
 at least one printed circuit board;    a packaged receiver near one end coupled to the at least one printed circuit board;    a packaged transmitter for high modulation bandwidth, the packaged transmitter near the one end and including 
 a thin-outline device package including a thin-outline header having a post with a first impedance;  
 a semiconductor laser mounted within the thin-outline device package, the semiconductor laser having an electrical contact with a second impedance;  
 an impedance-controlled circuit coupled between the post of the thin-outline header and the electrical contact of the semiconductor laser, the impedance-controlled circuit having a third impedance at one contact point and a fourth impedance at another contact point; and  
 wherein the third impedance of the impedance-controlled circuit to match the first impedance of the post of the thin-outline header, the fourth impedance of the impedance-controlled circuit to match the second impedance of the electrical contact of the semiconductor laser, and the impedance-controlled circuit to provide a low impedance in a first interconnect between the semiconductor laser and the impedance-controlled circuit and a low impedance in a second interconnect between the post of the thin-outline header and the impedance-controlled circuit for high modulation bandwidth; and  
   a housing.    
   
   
       86 . A fiber optic communication system comprising: 
 a first fiber optic module at one end;    a second fiber optic module at an opposite end;    at least one fiber optic cable coupled between the first fiber optic module and the second fiber optic module; and    at least one of the first fiber optic module and the second fiber optic module includes 
 at least one printed circuit board;  
 a packaged transmitter for high modulation bandwidth coupled to the at least one printed circuit board, the packaged transmitter including  
 a thin-outline device package including a header with a first pin and a second pin feeding through the header and a third pin coupled to a bottom of the header, the first pin being closer to a center of the header than the third pin, the first pin having a first feedthrough impedance and the second pin having a second feedthrough impedance,  
 a first feedthrough between the first pin and the header,  
 a second feedthrough between the second pin and the header,  
 a photodetector and a submount mounted within the thin-outline device package, a bottom surface of the photodetector and a bottom surface of the submount coupled to the header, the photodetector having an electrical contact on a top surface with a first input impedance,  
 a semiconductor laser mounted within the thin-outline device package, a bottom surface of the semiconductor laser coupled to a top surface of the submount, the semiconductor laser having an electrical contact on a top surface with a second input impedance,  
 a first bondwire with a first length coupled between a post of the first pin and the electrical contact of the semiconductor laser,  
 a second bondwire with a second length coupled between a post of the second pin and the electrical contact of the photodetector, and  
 wherein the first pin being closer to the center of the header than the third pin to minimize the first length and an inductance of the first bondwire; and  
   a housing.