High-density optical disk with a polymer film featuring thermochromism

Abstract

The present invention relates to a high-density optical disk having thin film layer made from a thermochromic polymer with a red-shift which exhibits self-focusing and optical bleaching. After an incident light beam passes through the polymer medium, not only can the spot size of the beam be reduced but also transmittance can be enhanced due to these kinds of third-order nonlinear optical response. Thus, a high-density disk structured according to the present invention is capable of the signal reproduction resolution beyond the diffraction limit with an efficient reflectivity. Accordingly, data recording density of a high-density disk can be improved greatly.

What is claimed is:  
     
         1 . A high-density disk recording medium, comprising: 
 a transmission layer;    a reflection layer;    a protective layer; and    a polymer film featuring thermochromism with a red-shift and situated adjacently to the transmission layer, wherein the polymer film refracts an incident light beam beyond diffraction limit of the incident light beam and allows the formation of a smaller laser beam spot on the reflective layer.    
     
     
         2 . The medium of  claim 1 , wherein the polymer film is disposed between the transmission layer and the reflection layer.  
     
     
         3 . The medium of  claim 1 , wherein the polymer film comprises poly (3-tetradecylthiophene)-co-(3-(4-trifluoromethyl-phenyl)thiophene).  
     
     
         4 . The medium of  claim 1 , wherein the polymer film has a thermochromism with a red-shift in which a refractive coefficient increases and an extinction coefficient decreases at a specific frequency due to an increase in temperature arising from light energy absorption.  
     
     
         5 . The medium of  claim 4 , wherein the polymer film refracts an incident light beam and allows the formation of a Gaussian beam spot at a light intensity between about 10 kW/cm 2  and 20 kW/cm 2 .  
     
     
         6 . A recordable disk medium for use with a light source, the medium comprising: 
 a transmission layer;    a reflection layer;    a protective layer; and    a polymer film featuring thermochromism and disposed coplanarly with the reflection layer in an incident light beam path of the light source wherein the polymer film refracts an incident light beam beyond a diffraction limit of the incident light beam and allows the formation of a smaller laser beam spot on the reflection layer.    
     
     
         7 . The recordable disk medium of  claim 6 , wherein the polymer film has a red-shift characteristic.  
     
     
         8 . The recordable disk medium of  claim 6 , wherein the polymer film is disposed between the transmission layer and the reflection layer.  
     
     
         9 . The recordable disk medium of  claim 6 , wherein the transmission layer is disposed between the polymer film and the reflection layer.  
     
     
         10 . The recordable disk medium of  claim 6 , wherein the polymer film comprises poly (3-tetradecylthiophene)-co-(3-(4-trifluoromethyl-phenyl)thiophene).  
     
     
         11 . The recordable disk medium of  claim 6 , wherein the polymer film with thermochromism has a refractive coefficient that increases and an extinction coefficient that decreases in response increased in temperature caused by absorbing energy from the incident light beam.  
     
     
         12 . The recordable disk medium of  claim 11 , wherein the polymer film refracts the incident light beam and allows the formation of a Gaussian beam spot at a light intensity between about 10 kW/cm 2  and 20 kW/cm 2 .  
     
     
         13 . A recording and reproduction apparatus for use with a disk medium, the apparatus comprising: 
 a light source that provide an incident light beam on the disk medium;    the disk medium comprising: 
 a transmission layer;  
 a reflection layer;  
 a protective layer; and  
 a polymer film having thermochromism disposed coplanarly with the reflection layer in an incident light beam path of the light source wherein the polymer film refracts the incident light beam beyond a diffraction limit of the incident light beam and allows the formation of a smaller laser beam spot on the reflection layer.  
   
     
     
         14 . The apparatus of  claim 13 , wherein the polymer film has a red-shift characteristic.  
     
     
         15 . The apparatus of  claim 13 , wherein the polymer film is disposed between the transmission layer and the reflection layer.  
     
     
         16 . The apparatus of  claim 13 , wherein the transmission layer is disposed between the polymer film and the reflection layer.  
     
     
         17 . The apparatus of  claim 13 , wherein the polymer film comprises poly (3-tetradecylthiophene)-co-(3-(4-trifluoromethyl-phenyl)thiophene).  
     
     
         18 . The apparatus of  claim 13 , wherein the polymer film with thermochromism has a refractive coefficient that increases and an extinction coefficient that decreases in response increased in temperature caused by absorbing energy from the incident light beam.  
     
     
         19 . The apparatus of  claim 18 , wherein the polymer film refracts the incident light beam and allows the formation of a Gaussian beam spot at a light intensity between about 10 kW/cm 2  and 20 kW/cm 2 .