Waveguide type optical device and manufacturing method thereof

Abstract

An array waveguide diffraction grating 201 as waveguide type optical device comprises a planer lightwave circuit 203 with an optical waveguide layer 211 formed on a silicon substrate 212 and having a predetermined thickness h 0 , a first compensation substrate 204 bonded to the side of the optical waveguide layer 211 and having a thickness h 1 and a second compensation substrate 205 formed on the silicon substrate 212 and having a thickness h 4 . The linear expansion coefficients α 1 and α 4 of the two compensation substrates 204 and 205 are set to be greater than that of the optical waveguide element 203 , and highly rigid adhesives are used as a first and a second adhesive 214 and 215 . It is thus possible to have the contraction of the optical waveguide element 203 due to a temperature change increased with the first and second substrates, thus permitting the center frequency setting to a desired value in a predetermined temperature range. Similar effects are obtainable by merely providing a support substrate on the substrate side of the optical waveguide element 203.

1 - 9 . (canceled)  
   
   
       10 . A method of manufacturing a waveguide type optical device comprising: 
 an element preparation step of preparing an optical waveguide element;    a checking step for checking whether the center wavelength of the prepared optical waveguide element can be set to a predetermined value under temperature control in a predetermined temperature range; and    a bonding step of bonding, to the substrate side of an optical waveguide element having judged in the checking step to be incapable of setting the desired value, a support substrate having a predetermined linear expansion coefficient greater than that of the substrate itself of the optical waveguide element.    
   
   
       11 . A method of manufacturing a waveguide type optical device comprising: 
 an element preparation step of preparing an optical waveguide element; and    a bonding step for bonding, to the substrate side of optical waveguide element prepared in the element preparation step, a support substrate having a predetermined linear expansion coefficient greater than that of the substrate itself of the optical waveguide element.    
   
   
       12 . The waveguide type optical device according to  claim 10 , wherein the adhesive used for bonding in the bonding step is highly rigid when hardened.  
   
   
       13 . A method of manufacturing a waveguide type optical device comprising: 
 an element preparation step of preparing an optical waveguide element;    a checking step for checking whether the center wavelength of the prepared optical waveguide element can be set to a desired value under temperature control in a predetermined temperature range;    a first substrate bonding step of bonding, to the waveguide side of an optical waveguide element judged in the checking step to be incapable of setting the desired value, a first substrate having a linear expansion coefficient greater than that of the substrate itself of the optical waveguide element; and    a second step of bonding, to the substrate side of the optical waveguide element judged in the checking step to be incapable of setting the desired value, a second substrate having a linear expansion coefficient greater than that of the substrate itself of the optical waveguide element.    
   
   
       14 . A method of manufacturing a waveguide type optical device comprising: 
 an element preparation step of preparing an optical waveguide element;    a first substrate bonding step of bonding, to the waveguide side of the optical waveguide element prepared in the element preparation step a first substrate having a linear expansion coefficient greater than that of the substrate itself of the optical waveguide element; and    a second step of bonding, to the substrate side of the optical waveguide element prepared in the element preparation step a second substrate having a linear expansion coefficient greater than that of the substrate itself of the optical waveguide element.    
   
   
       15 . The waveguide type optical device according to  claim 13 , wherein the first and second substrates are substantially equal in thickness and linear expansion coefficient.  
   
   
       16 . A method of manufacturing a waveguide type optical device comprising: 
 an element preparation step of preparing an optical waveguide element;    a temperature measuring step of measuring a temperature, at which the center wavelength of the prepared optical waveguide element is set to a desired value;    a support substrate linear expansion coefficient selecting step of selecting the extent, by which the linear expansion coefficient of the support substrate to be bonded to the substrate side of the optical waveguide element is greater than that of the substrate in the optical waveguide element, on the basis of the temperature measured in the ideal temperature measuring step; and    a bonding step of bonding, to the substrate side of the optical waveguide element, a support substrate having the linear expansion coefficient selected in the support substrate linear expansion coefficient selecting step.    
   
   
       17 . A method of manufacturing a waveguide type optical device comprising: 
 an element preparation step of preparing an optical waveguide element;    a temperature measuring step of measuring a temperature, at which the center wavelength of the prepared optical waveguide element is set to a desired value;    a first/second substrate linear expansion coefficient selecting step of selecting the extent, by which the linear expansion coefficient of the first substrate to be bonded to the waveguide side of the optical waveguide element and the liner expansion coefficient of the second substrate to be bonded to the substrate side of the optical waveguide element are greater than that of the substrate of the optical waveguide element, on the basis of the temperature measured in the ideal temperature measuring step; and    bonding step of bonding the first and second substrates with the linear expansion coefficient selected in the first/second substrate linear expansion coefficient selecting step to corresponding parts of the optical waveguide element.    
   
   
       18 . The waveguide type optical device according to  claim 11 , wherein the adhesive used for bonding in the bonding step is highly rigid when hardened.  
   
   
       19 . The waveguide type optical device according to  claim 14 , wherein the first and second substrates are substantially equal in thickness and linear expansion coefficient.