Near-field hybrid magnetic-optical head system

Abstract

A hybrid magnetic-optical head apparatus wherein one or more solid state lasers, magnetic field biasing elements, magnetic sensing elements, and an aerodynamically shaped slider comprise a single integrated, monolithic device fabricated from the same base semiconductor material into an optical head. The monolithic optical head can be quickly and easily attached to the read arm of an optical read/write device without requiring attachment of separate laser and magnetic elements, and without micropositioning or use of optical microscopy for positioning the lasers or magnetic elements. The hybrid magnetic-optical head apparatus includes a magnetic-optical function region having a semiconductor laser and at least one magnetic element. Preferably, the magnetic-optical function region of the substrate includes a magnetic field biasing element associated with the semiconductor laser, as well as a magnetic sensing element. The slider portion of the magnetic optical head preferably includes an aerodynamically shaped air cavity as well as an air bearing surface, with the emission face of the laser preferably is substantially co-planar with the air bearing surface. The magneticoptical function region may be configured for magnetically assisted thermal recording wherein writing is carried out primarily by laser power modulation to selectively heat portions of a medium, together with assistance of an applied magnetic field to establish a preferred direction of magnetization pattern in the medium. The magnetic-optical function region may alternatively be configured for thermally assisted magnetic writing wherein writing is carried out primarily by modulation of magnetic field, together with assistance of a laser which heats the medium to reduce the medium coercivity and thereby assist in the magnetic recording.

1 . An apparatus comprising: 
 a slider;    at least one laser; and    at least one magnetic element, the magnetic element surrounding an emission facet of the laser, the slider, the laser and the magnetic element comprising integral components of a monolithic semiconductor substrate.    
     
     
         2 . The apparatus of  claim 1 , wherein the at least one magnetic element comprises a magnetic field biasing element.  
     
     
         3 . The apparatus of  claim 1 , wherein the at least one magnetic element further comprises a magnetic sensor element.  
     
     
         4 . An apparatus comprising a semiconductor substrate, the semiconductor substrate structured and configured to define a slider, at least one laser and at least one magnetic element, the laser and the magnetic element integral with the slider, the magnetic element surrounding an emission facet.  
     
     
         5 . The apparatus of  claim 4 , wherein the magnetic element is recessed with respect to the emission facet of the laser.  
     
     
         6 . The apparatus of  claim 4 , wherein the laser is a vertical cavity surface emitting laser.  
     
     
         7 . An apparatus comprising a monolithic semiconductor substrate, the monolithic semiconductor substrate including a slider portion having an air bearing surface, a magnetic-optical function region having at least one laser and at least one magnetic element surrounding a facet of the laser.  
     
     
         8 . The apparatus of  claim 7  wherein the magnetic element is recessed with respect to the facet.  
     
     
         9 . The apparatus of  claim 7  wherein the magnetic element comprises a sensor element, sensor element integral with the monolithic semiconductor substrate.  
     
     
         10 . The magnetic optical head apparatus of  claim 7 , wherein the magnetic element comprises a conductive coil positioned in association with an emission facet of the semiconductor laser.  
     
     
         11 . The magnetic optical head apparatus of  claim 7 , wherein the magnetic element comprises a yoke of soft magnetic material positioned in association with an emission facet of the semiconductor, a first conductive coil associated with the yoke, and a second conductive coil associated with the yoke.  
     
     
         12 . The apparatus of  claim 9 , wherein the magnetic sensor element comprises a giant magneto-resistive sensor.  
     
     
         13 . The apparatus of  claim 7  wherein the facet has an aperture.  
     
     
         14 . The apparatus of  claim 13  wherein the laser has an output wavelength λ and the aperture has a width w, such that w<λ.  
     
     
         15 . A system comprising: 
 a monolithic semiconductor substrate; and    an optical head comprising a laser, a biasing element, a sensor element and a slider, the optical head integral to the monolithic semiconductor substrate, the laser including a facet having an aperture.    
     
     
         16 . The system of  claim 15  further comprising an optical medium, the optical medium being positioned adjacent the optical head, the optical medium including a read layer.  
     
     
         17 . The system of  claim 15  further comprising an optical medium wherein the optical medium is positioned adjacent the optical head including a memory layer.  
     
     
         18 . The system of  claim 16  wherein the aperture has a width w, which is smaller than an output wavelength λ of the laser.  
     
     
         19 . The system of  claim 18  wherein the read layer is separated from the facet by an optical path-length d, wherein d is less than the output wavelength λ.  
     
     
         20 . The system of  claim 19  wherein w<λ/2 and d<w/2.  
     
     
         21 . A method, comprising: 
 providing an optical head, the optical head comprising a monolithic semiconductor substrate, the optical head including at least one laser, at least one biasing element, at least one sensor element, and a slider, the optical head integral to the monolithic substrate, the laser comprises a facet that has an aperture; and    positioning an optical medium adjacent the magnetic optical head.    
     
     
         22 . The method of  claim 21  further comprising flying the optical head over the optical medium, the optical medium including a read layer and a memory layer.  
     
     
         23 . The method of  claim 22 , wherein the aperture has a width w, which is smaller than an output wavelength λ of the laser.  
     
     
         24 . The method of  claim 23 , wherein the positioning of the optical head is carried out by positioning the facet apart from the read layer by an optical path length d, wherein the optical path-length d is smaller than the output wavelength λ.  
     
     
         25 . A method comprising: 
 preparing a semiconductor substrate;    defining a slider region on the semiconductor substrate; and    defining an optical function region on the semiconductor substrate wherein the defining the optical function region comprises forming a conductive coil surrounding a facet.    
     
     
         26 . The method of  claim 25 , wherein the preparing the semiconductor substrate comprises: 
 providing a base layer of first conductivity-type semiconductor;    depositing a first conductivity-type clad layer on the base layer of first conductivity-type semiconductor;    depositing an active region layer on the first conductivity-type clad layer; and    depositing a second conductivity-type clad layer on the active region layer;    the base layer defining a first side of the semiconductor substrate, the second conductivity type layer defining a second side of the semiconductor substrate.    
     
     
         27 . The method of  claim 26 , wherein the defining the optical function region further comprises: 
 depositing a second side electrical contact on second conductivity-type clad layer, the second side contact configured to define the facet for the laser region, the second side electrical contact positioned lower than the facet; and    depositing a first side electrical contact adjacent the first conductivity-type semiconductor layer;    the second side electrical contact and the first side electrical contact being structured and configured to define a diode structure a laser.    
     
     
         28 . The method of  claim 27 , wherein the facet is an emission facet of the semiconductor laser.  
     
     
         29 . The method of  claim 28 , wherein the defining the optical function region further comprises forming a giant magneto-resistive read element proximate the second side of the semiconductor substrate.  
     
     
         30 . The method of  claim 25  wherein the facet has an aperture.