Optical device, and semiconductor laser oscillator

Abstract

In an optical device, a slab layer includes an active layer sandwiched between cladding layers. The slab layer has a periodic refractive index profile structure in a two-dimensional plane, as a two-dimensional slab photonic crystal structure, and a linear defect region serving as a waveguide in the periodic refractive index profile structure. Regions having different widths of the waveguides, as segments of the waveguide, are connected in series.

1 - 10 . (canceled) 
     
     
         11 . An optical device including a slab layer comprising, laminated, an active layer and cladding layers, spreading two-dimensionally, having a periodic refractive index profile structure in a two-dimensional plane, a two-dimensional slab photonic crystal structure including a linear defect region serving as a waveguide in the periodic refractive index profile structure, and a plurality of regions having different lattice constants that constitute the periodic refractive index profile structure, arranged so that segments of the waveguide are connected in series. 
     
     
         12 . The optical device according to  claim 11 , wherein the regions extend in a direction in which the waveguide extends and the lattice constants that constitute the periodic refractive index profile structure of the regions decrease gradually. 
     
     
         13 . The optical device according to  claim 11 , wherein one end of two ends of the segments connected in series in the optical device is used as an emission port of the waveguide, emitting light oscillating in the regions. 
     
     
         14 . The optical device according to  claim 11 , wherein, in a direction in which the waveguide extends, length is different in each of the regions. 
     
     
         15 . The optical device according to  claim 11 , including electrodes for controlling respective regions, located substantially parallel to a direction in which the waveguide extends, wherein at least one of the electrodes is divided in one of the regions. 
     
     
         16 . The optical device according to  claim 11 , further comprising a control unit that controls magnitudes of currents applied to the electrodes. 
     
     
         17 . A semiconductor laser oscillator comprising:
 an optical device including a slab layer comprising, laminated, an active layer and cladding layers, spreading two-dimensionally, having a periodic refractive index profile structure in a two-dimensional plane, and a two-dimensional slab photonic crystal structure including a linear defect region serving as a waveguide in the periodic refractive index profile structure, wherein   the waveguide includes a plurality of regions having different lattice constants that constitute the periodic refractive index profile structure, arranged so that segments of the waveguide are connected in series, and
 the semiconductor laser oscillator simultaneously actuates all of the regions of the optical device and collects laser light from all of the regions, from an end of the segments of the waveguide connected in series. 
   
     
     
         18 . The semiconductor laser oscillator according to  claim 17 , further comprising a temperature adjustment unit that adjusts temperature of the optical device to a fixed temperature. 
     
     
         19 . A semiconductor laser oscillator comprising:
 an optical device including a slab layer comprising, laminated, an active layer and cladding layers, spreading two-dimensionally, having a periodic refractive index profile structure in a two-dimensional plane, and a two-dimensional slab photonic crystal structure including a linear defect region serving as a waveguide in the periodic refractive index profile structure, and   a plurality of regions having different lattice constants that constitute the periodic refractive index profile structure, arranged so that segments of the waveguide are connected in series, wherein the semiconductor laser oscillator actuates one of the regions of the optical device and collects laser light from the region actuated at an end of the segments of the waveguide connected in series.   
     
     
         20 . The semiconductor laser oscillator according to  claim 19 , further comprising a temperature adjustment unit that adjusts temperature of the optical device to a fixed temperature. 
     
     
         21 - 43 . (canceled)