Semiconductor laser module, optical measuring method and optical measuring apparatus

• US 20030021311A1
• Filed: 07/12/2002
• Published: 01/30/2003
• Est. Priority Date: 07/25/2001
• Status: Active Grant

• Current Assignee: Furukawa Electric Company Limited
• Original Assignee: Furukawa Electric Company Limited
• Inventors: Tsukiji, Naoki, Yoshida, Junji, Koseki, Takashi, Hayamizu, Naoki, Tsunetomo, Kohei
• Granted Patent: US 6,901,095 B2
• Time in Patent Office: Days
• US Class Current: 372/36
• CPC Class Codes: H01S 5/02212 Can-type, e.g. TO-CAN housings with emission along or parallel to symmetry axis
• CPC Class Codes: H01S 5/0222 Gas-filled housings
• CPC Class Codes: H01S 5/02235 Getter material for absorbing contamination
• CPC Class Codes: H01S 5/02251 using optical fibres
• CPC Class Codes: H01S 5/02415 by using a thermo-electric cooler [TEC], e.g. Peltier element
• CPC Class Codes: H01S 5/02438 Characterized by cooling of elements other than the laser chip, e.g. an optical element being part of an external cavity or a collimating lens
• CPC Class Codes: H01S 5/0683 by monitoring the optical output parameters

Abstract

A package accommodates an LD device for emitting laser light with the center wavelength of which is in a range of 1300 to 1440 nm and airtight seals a light path extending from the LD device to an incident end of an optical fiber. The package is filled with a nitrogen gas at a standard atmospheric pressure with the amount of moisture limited to a value lower than 100000 ppm by volume or less. Therefore, the amount of moisture in the light path for laser light within the package is limited to 100000 ppm by volume or less.

Claims

1. A semiconductor laser module comprising:

a semiconductor laser device configured to emit a laser light, the laser light having a center wavelength in an inclusive range of 1300 nm through 1440 nm;

an optical fiber configured to receive and guide the laser light emitted from said semiconductor laser device; and

a package configured to accommodate said semiconductor laser device therein and provide an airtight sealed environment for a light path for the laser light that extends at least from said semiconductor laser device to an incident end of said optical fiber, said optical fiber extending from said package,

wherein an amount of moisture in said package is limited to 100000 ppm by volume or less.

2. The module according to claim 1, further comprising:

an optical element disposed in said light path within said package,

wherein a total of the amount of moisture in said package and an amount of moisture contained in said optical element is limited to 100000 ppm by volume or less.

3. The module according to claim 1, further comprising:

a getter disposed in said package and configured to absorb moisture.

4. The module according to claim 1, wherein:

said package includes

an opening portion through which said optical fiber is inserted; and

a seal configured to hermetically seal a gap between said optical fiber and an inner wall of the opening portion of said package.

5. The module according to claim 4, wherein said seal includes at least one of an adhesive and a resin that closes the gap.

6. The module according to claim 4, wherein said seal includes solder that closes the gap.

7. The module according to claim 4, wherein said seal includes a seam that closes the gap, said seam being a laser welded seam.

8. The module according to claim 4, wherein said seal includes a covering member for airtight sealing a region between said optical fiber and said package.

9. The module according to claim 1, wherein:

said package includes

an opening portion through which said optical fiber is inserted; and

sealing means for hermetically sealing a gap between said optical fiber and an inner wall of the opening portion of said package.

10. The module according to claim 9, wherein said sealing means includes means for airtight sealing a region between said optical fiber and said package.

11. An optical measuring method comprising steps of:

limiting an amount of moisture in a light path for a laser light to 100000 ppm by volume or less;

emitting said laser light from an output end of an optical fiber to said light path, said laser light having a center wavelength in an inclusive range of 1300 nm through 1440 nm; and

measuring a characteristic of the laser light when the laser light travels in the light path.

12. The method according to claim 11, wherein:

said emitting step includes emitting said laser light through an optical element disposed in said light path within said package; and

said limiting step includes limiting a total of the amount of moisture in said package and an amount of moisture contained in said optical element to 100000 ppm by volume or less.

13. The method according to claim 11, wherein:

said limiting step includes absorbing said moisture with a getter disposed in said package.

14. The method according to claim 11, wherein:

said limiting step includes hermetically sealing a gap between said optical fiber and an inner wall of an opening portion formed in a wall of said package.

15. The method according to claim 14, wherein said hermetically sealing step includes closing the gap with at least one of an adhesive and a resin.

16. The method according to claim 14, wherein said hermetically sealing step includes closing the gap with solder.

17. The method according to claim 14, wherein said hermetically sealing step includes laser welding a seam so as to close said gap.

18. The method according to claim 14, wherein said hermetically sealing step includes applying a covering so as to airtightly seal a region between said optical fiber and said package.

19. An optical measuring apparatus comprising:

a measuring device configured to receive laser light with a center wavelength in an inclusive range of 1300 nm through 1440 nm, emitted from an output end of an optical fiber, and configured to measure a characteristic of said laser light while said laser light travels along a light path; and

a main container configured to accommodate said measuring device therein and provide and airtight sealed environment for at least a spatial propagation path portion of said light path for said laser light that extends from the output end of said optical fiber to said measuring device,

wherein an amount of moisture in said main container is limited to 100000 ppm by volume or less.

20. The apparatus according to claim 19, further comprising:

an optical element disposed in said light path within said main container, said optical element having an internal spatial propagation path.

21. The apparatus according to claim 19, wherein:

said main container comprises an inlet/outlet port configured to introduce and remove said optical fiber and a semiconductor laser module configured to emit said laser light to said optical fiber therein; and

said inlet/outlet port being configured to remain airtightly closed after said optical fiber and said semiconductor laser module are introduced into said main container.

22. The apparatus according to claim 19, wherein said apparatus further comprises:

a sub container including a transfer port configured to connect said sub container to said main container and an inlet/outlet port configured to introduce and remove said optical fiber and a semiconductor laser module that emits said laser light to said optical fiber, wherein

said inlet/output port and said transfer port are configured to remain airtightly closed after said optical fiber and said semiconductor laser module are introduced into said sub container, and

said optical fiber and said semiconductor laser module are accommodated in said sub container with an amount of moisture in said sub container being limited to 100000 ppm by volume or less.

23. The apparatus according to claim 20, wherein:

said main container includes a first chamber that accommodates said measuring device, and a second chamber that accommodates said optical element;

said second chamber comprises an inlet/outlet port configured to introduce and remove said optical fiber and a semiconductor laser module that emits said laser light to said optical fiber into said second chamber; and

said inlet/output port is configured to remain airtightly closed after said optical fiber and said semiconductor laser module are introduced into said second chamber.

24. The apparatus according to claim 19, wherein said main container comprises an optical connection configured to removably connect the output end of said optical fiber from outside of said main container.

25. An optical measuring apparatus comprising:

a measuring device configured to receive and measure a characteristic of a laser light with a center wavelength in an inclusive range of 1300 nm through 1440 nm that is emitted from an output end of an optical fiber; and

a light path for said laser light being in a form of an optical fiber based optical element, said light path extending from an output end of said optical fiber to said measuring device.

26. The apparatus according to claim 25, further comprising:

sealing means for hermetically sealing an internal spatial propagation path of said measuring device with an amount of moisture limited to 100000 ppm by volume or less.