Diffraction grating and dispersion compensation circuit

• US 20080056643A1
• Filed: 08/02/2007
• Published: 03/06/2008
• Est. Priority Date: 08/04/2006
• Status: Active Grant

• Current Assignee: KEIO University, Hitachi Cable Limited (Proterial Ltd.)
• Original Assignee: KEIO University, Hitachi Cable Limited (Proterial Ltd.)
• Inventors: Ishikawa, Hiroshi, Tsuda, Hiroyuki, Uetsuka, Hisato
• Granted Patent: US 7,496,256 B2
• Time in Patent Office: Days
• US Class Current: 385/37
• CPC Class Codes: G02B 6/12011 characterised by the arrayed waveguides, e.g. comprising a filled groove in the array section
• CPC Class Codes: G02B 6/12014 characterised by the wavefront splitting or combining section, e.g. grooves or optical elements in a slab waveguide
• CPC Class Codes: G02B 6/12021 Comprising cascaded AWG devices; AWG multipass configuration; Plural AWG devices integrated on a single chip
• CPC Class Codes: G02B 6/12026 characterised by means for reducing the temperature dependence
• CPC Class Codes: G02B 6/12033 characterised by means for configuring the device, e.g. moveable element for wavelength tuning switching G02B6/35; thermo-optic devices G02F1/0147
• CPC Class Codes: G02B 6/1221 made from organic materials
• CPC Class Codes: G02B 6/29394 Compensating wavelength dispersion G02B6/29376 takes precedence; dispersion compensated optical transmission systems H04B10/2507
• CPC Class Codes: G02B 6/29395 configurable, e.g. tunable or reconfigurable switching G02B6/35
• CPC Class Codes: G02B 6/29398 Temperature insensitivity

Abstract

A diffraction grating of the present invention includes a first block (101) and a second block (102). The first block (101) is made up of a plurality of input waveguides (103), a slab waveguide (104), a delay waveguide array (105) and narrow grooves (106): each of which being filled with resin. The second block (102) is made up of a plurality of input waveguides (107), a slab waveguide (108) and a plurality of output waveguides (109). Since a circuit is cut off at the ends of the arrayed waveguides, a relative phase can easily be measured. The resin has undergone a refractive-index adjustment and compensates a phase error.

Claims

1. A diffraction grating comprising:

(a) a first block, the first block including;

a plurality of first input waveguides;

a first star coupler connected to the first input waveguides;

a plurality of delay waveguides connected to the first star coupler; and

grooves that are provided instead of a part of the delay waveguides, each of which being filled with an organic material; and

(b) a second block connected to the first block, the second block including;

a plurality of second input waveguides;

a second star coupler connected to the second input waveguides; and

a plurality of output waveguides connected to the second star coupler.

2. A diffraction grating comprising a first block, a second block, a third block and a fourth block, the first to fourth blocks being connected together, both ends of a series of the first to fourth blocks being occupied by the first block and the fourth block, respectively,

(a) the first block including:

a plurality of first input waveguides;

a first star coupler connected to the first input waveguides; and

a plurality of first output waveguides connected to the first star coupler;

(b) the second block having a plurality of groove structures that are formed on a substrate and in each of which a holey fiber is embedded;

(c) the third block including;

a plurality of delay waveguides; and

grooves that are provided instead of a part of the delay waveguides, each of which being filled with an organic material; and

(d) the fourth block including;

a plurality of second input waveguides;

a second star coupler connected to the second input waveguides; and

a plurality of second output waveguides connected to the second star coupler.

3. A dispersion compensation circuit comprising:

(a) a first block, the first block including;

a plurality of first input waveguides;

a star coupler connected to the first input waveguides;

a plurality of delay waveguides connected to the star coupler; and

grooves that are provided instead of a part of the delay waveguides, each of which being filled with an organic material; and

(b) a second block connected to the first block, the second block including;

a plurality of second input waveguides;

a slab waveguide connected to the second input waveguide;

grooves that are provided on an optical path of the slab waveguide, each of which being filled with an organic material;

a heater provided around the grooves; and

a mirror that is provided at an end of the slab waveguide and that is disposed on an end face of a substrate.

4. A dispersion compensation circuit comprising a first block, a second block, a third block and a fourth block, the first to fourth blocks being connected together, both ends of a series of the first to fourth blocks being occupied by the first block and the fourth block, respectively,

(a) the first block including:

a plurality of first input waveguides;

a first star coupler connected to the first input waveguides; and

a plurality of output waveguides connected to the first star coupler;

(b) the second block having a plurality of groove structures that are formed on a substrate and in each of which a holey fiber is embedded;

(c) the third block including;

a plurality of delay waveguides; and

grooves that are provided instead of a part of the delay waveguides, each of which being filled with an organic material; and

(d) the fourth block including;

a plurality of second input waveguides;

a slab waveguide connected to the second input waveguides;

grooves that are provided on an optical path of the slab waveguide, each of which being filled with an organic material;

a heater provided around the grooves; and

a mirror that is provided at an end of the slab waveguide and that is disposed on an end face of a substrate.

5. A dispersion compensation circuit comprising a first block, a second block and a third block, the first to third blocks being connected together in this order,

(a) the first block including:

a plurality of first input waveguides;

a first star coupler connected to the first input waveguides;

a plurality of first delay waveguides connected to the first star coupler; and

first grooves that are provided instead of a part of the first delay waveguides, each of which being filled with an organic material;

(b) the second block including;

a plurality of second input waveguides;

a slab waveguide connected to the second input waveguides;

second grooves that are provided on an optical path of the slab waveguide, each of which being filled with an organic material;

a heater provided around the second grooves; and

a plurality of second output waveguides connected to the slab waveguide; and

(c) the third block including;

a plurality of second delay waveguides;

third grooves that are provided instead of a part of the second delay waveguides, each of which being filled with an organic material; and

a second star coupler connected to the second delay waveguides; and

a plurality of third output waveguides connected to the second star coupler.

6. A dispersion compensation circuit comprising a first block, a second block, a third block, a fourth block, a fifth block, a sixth block and a seventh block, the first to seventh blocks being connected together in this order,

(a) the first block including:

a plurality of first input waveguides;

a first star coupler connected to the first input waveguides; and

a plurality of first output waveguides connected to the first star coupler;

(b) the second block having a plurality of first groove structures that are formed on a substrate and in each of which a first holey fiber is embedded;

(c) the third block including;

a plurality of delay waveguides; and

first grooves that are provided instead of a part of the delay waveguides, each of which being filled with an organic material;

(d) the fourth block including;

a plurality of second input waveguides;

a slab waveguide connected to the second input waveguides;

second grooves that are provided on an optical path of the slab waveguide, each of which being filled with an organic material;

a heater provided around the second grooves; and

a plurality of second output waveguides connected to the slab waveguide;

(e) the fifth block including;

a plurality of second delay waveguides; and

third grooves that are provided instead of a part of the second delay waveguides, each of which being filled with an organic material;

(f) the sixth block having a plurality of second groove structures that are formed on the substrate and in each of which a second holey fiber is embedded;

(g) the seventh block including;

a plurality of third input waveguides;

a second star coupler connected to the third input waveguides; and

a plurality of third output waveguides connected to the second star coupler.

7. A diffraction grating comprising a first block, a second block, a third block and a fourth block, the first to fourth blocks being connected together, both ends of a series of the first to fourth blocks being occupied by the first block and the fourth block, respectively,

(a) the first block including:

a plurality of first input waveguides;

a first star coupler connected to the first input waveguides; and

a plurality of first output waveguides connected to the first star coupler;

(b) the second block including;

an input waveguide substrate having a plurality of second input waveguides;

substrates, each of which has a delay waveguide or a delay line in which a holey fiber is embedded, the delay waveguide or the delay line being connected to the second input waveguides, respectively, of the input waveguide substrate; and

an output waveguide substrate having a plurality of second output waveguides, each of which being connected to the delay waveguide or to the delay line of the substrate;

(c) the third block including;

a plurality of delay waveguides; and

grooves that are provided instead of a part of the delay waveguides, each of which being filled with an organic material;

(d) the fourth block including;

a plurality of third input waveguides;

a second star coupler connected to the third input waveguide; and

a plurality of third output waveguides connected to the second star coupler.

8. A diffraction grating comprising a first block, a second block, a third block and a fourth block, the first to fourth blocks being connected together, both ends of a series of the first to fourth blocks being occupied by the first block and the fourth block, respectively,

(a) the first block including:

a plurality of first input waveguides;

a first star coupler connected to the first input waveguides; and

a plurality of first output waveguides connected to the first star coupler;

(b) the second block including;

an input waveguide substrate having a plurality of second input waveguides;

a cylindrical bobbin on which holey fibers connected to the second input waveguides, respectively, of the input waveguide substrate are wound; and

an output waveguide substrate having a plurality of second output waveguides connected to the holey fibers, respectively;

(c) the third block including;

a plurality of delay waveguides; and

grooves that are provided instead of a part of the delay waveguides, each of which being filled with an organic material; and

(d) the fourth block including;

a plurality of third input waveguides;

a second star coupler connected to the third input waveguides; and

a plurality of third output waveguides connected to the second star coupler.