Variable wavelength light source

• US 20040057472A1
• Filed: 10/30/2003
• Published: 03/25/2004
• Est. Priority Date: 09/26/2000
• Status: Active Grant

• Current Assignee: Hamamatsu Photonics KK
• Original Assignee: Hamamatsu Photonics KK
• Inventors: Yamanaka, Junpei, Itoh, Kensaku, Takiguchi, Yoshihiro
• Granted Patent: US 7,088,747 B2
• Time in Patent Office: Days
• US Class Current: 372/20
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 6/1225 comprising photonic band-gap structures or photonic lattices
• CPC Class Codes: G02B 6/266 the optical element being an attenuator
• CPC Class Codes: G02B 6/4204 the coupling comprising intermediate optical elements, e.g. lenses, holograms encapsulated active devices H01S5/02208, H01L33/52
• CPC Class Codes: G02B 6/4206 Optical features G02B6/4207, G02B6/421 take precedence
• CPC Class Codes: H01S 3/0078 Frequency filtering
• CPC Class Codes: H01S 3/1053 Control by pressure or deformation
• CPC Class Codes: H01S 3/106 by controlling devices placed within the cavity H01S3/10076, H01S3/13 take precedence
• CPC Class Codes: H01S 3/1623 chromium, e.g. Alexandrite
• CPC Class Codes: H01S 3/1625 titanium
• CPC Class Codes: H01S 3/1636 Al2O3 (Sapphire)
• CPC Class Codes: H01S 3/1648 with the formula XYZF6 (Colquiriite structure), wherein X is Li, Na, K or Rb, Y is Mg, Ca, Sr, Cd or Ba and Z is Al, Sc or Ga
• CPC Class Codes: H01S 3/1651 SrAlF5
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/0078 for frequency filtering
• CPC Class Codes: H01S 5/11 Comprising a photonic bandgap structure
• CPC Class Codes: H01S 5/141 using a wavelength selective device, e.g. a grating or etalon H01S5/146 takes precedence

Abstract

When a piezoelectric element 3 applies an external force to a plastic photonic crystal, the photonic crystal deforms, and accordingly, the photonic band gap easily changes. When the photonic band gap changes, transmission of light with a specific wavelength is limited. Therefore, light with a desired wavelength is outputted from the photonic crystal 2 upon sufficient tuning, and extracted to the outside through an output window 6. In the present invention, a plastic photonic crystal 2 which can achieve sufficient wavelength tuning although it is small is used, and elements are unitized, so that the entire wavelength tunable light source unit is downsized.

Claims

1. A wavelength tunable light source unit comprising:

a plastic photonic crystal;

external force applying means for applying an external force to said photonic crystal;

a light source for inputting light with a plurality of wavelengths into said photonic crystal; and

an output part for outputting light in a predetermined waveband that is selected by the photonic crystal, which are installed in a unit.

2. The wavelength tunable light source unit according to claim 1, wherein said light source is a lamp.

3. The wavelength tunable light source unit according to claim 1, wherein said light source is a laser light source.

4. The wavelength tunable light source unit according to claim 3, wherein the laser light source is a semiconductor laser having two opposed end faces for emitting light, light outputted from one of the end faces is inputted to a reflecting mirror through said photonic crystal, a laser resonator is constructed between said reflecting mirror and the other one of the end faces, and the other end face is optically coupled with said output part, and the waveband of light to be outputted from said output part changes in accordance with an external force applied by said external force applying means.

5. The wavelength tunable light source unit according to claim 1, wherein said laser light source is a titanium sapphire laser including a resonator, said photonic crystal being arranged in said resonator.