Device and method for tuning the wavelength of the light in an external cavity laser

{
  "publication_number": "US2002024979A1",
  "country": "US",
  "kind": "A1",
  "title": "Device and method for tuning the wavelength of the light in an external cavity laser",
  "abstract": "The invention relates to a device (300) for tuning the wavelength of the light in an external cavity laser. The external cavity laser comprises an optically amplifying semiconductor chip (310), a first reflecting surface (312), an Anti-Reflection (AR) coated semiconductor chip facet (314), a diffraction grating (330) on which at least part of the beam originating from the AR coated semiconductor chip facet (314) is incident and diffracted back to the optically amplifying semiconductor chip (310), means (320) for collimating the light emitted from the AR coated semiconductor chip facet (314) towards the diffraction grating (330), and a movable part (360) by means of the movement of this said part the wavelength of the light can be tuned in the external cavity laser. The movable part (360) of the external cavity laser exhibits a rotational movement relative to the optical axis of the external cavity laser, the optical axis being defined by the center of the beam propagating between the first and the second reflecting surface, said movement being actuated by an electrodynamic force generated within an integral section of said movable part.",
  "claims": [
    "1. Device (300) for tuning the wavelength of the light in an external cavity laser comprising an optically amplifying semiconductor chip (310), a first reflecting surface (312), an Anti-Reflection (AR) coated semiconductor chip facet (314) and a diffraction grating (330) on which at least part of the beam originating from the AR coated semiconductor chip facet (314) is incident and diffracted back to the optically amplifying semiconductor chip (310), means (320) for collimating the light emitted from the AR coated semiconductor chip facet (314) towards the diffraction grating (330), and a movable part (360) by means of the movement of which said part the wavelength of the light can be tuned in the external cavity laser, characterized in that the movable part (360) of the external cavity laser exhibits a rotational movement relative to the optical axis of the external cavity laser, the optical axis being defined by the center of the beam propagating between the first and the second reflecting surface, said movement being actuated by an electrodynamic force generated within an integral section of said movable part. 2. Device (300) according to claim 1, in which the movable part of the device consists of a rotatable arm (360) on which the diffraction grating (330) of the device is arranged. 3. Device (300) according to claim 1, also comprising an auxiliary mirror (150) on which at least part of the light diffracted from the diffraction grating (330) is incident and reflected back towards the diffraction grating, in which device said movable part consists of a rotatable arm on which the auxiliary mirror (150) is arranged. 4. Device (300) according to any one of the preceding claims, in which the integral section of the movable part (360), where an electrodynamic force is produced, comprises a first magnet (370), with the electrodynamic force being produced in interaction with a stationary first coil (374) though which electrical current is passed. 5. Device (300) according to any one of the preceding claims 1 - 3, in which the integral section of the movable part (360), where an electrodynamic force is produced, comprises a first coil (374) though which electrical current is passed, with the electrodynamic force being produced in interaction with a stationary first magnet (370). 6. Device (300) according to any one of the preceding claims, also comprising at least one second coil (376) and, associated with it, at least one second magnet (372), the electromagnetic interaction of which is used for detecting movement of the movable part (360). 7. Device (300) according to claim 6, where the detected movement of the movable part (360) can in turn be used in a control system for improving the control of the wavelength of the light in the external cavity laser. 8. Device (300) according to any one of the preceding claims, also comprising means (380, 485) for detecting the position of the movable part (360), where the position of the movable part is used in said control system for controlling the wavelength of the light in the external cavity laser. 9. Device according to claim 8, in which the means for detecting the position of the rotatable arm comprise a Position Sensitive Detector (PSD) (385) and a secondary light source (480) which is used for generating light which is detected by the PSD. 10. Method for tuning the wavelength of the light in an external cavity laser comprising an optically amplifying semiconductor chip (310), a first reflecting surface (312), an anti-reflection (AR) coated semiconductor chip facet (314) and a diffraction grating (330) on which at least part of the beam originating from the AR coated semiconductor chip facet (314) is incident and diffracted back to the optically amplifying semiconductor chip (310), means (320) for collimating the light emitted from the AR coated semiconductor chip facet (314) towards the diffraction grating (330), and a movable part (360) by means of the movement of this said part the wavelength of the light can be tuned in the external cavity laser, characterized in that the method comprises providing a rotational movement of the movable part (360) of the external cavity laser by means of an electrodynamic force, being produced in an integral section of the movable part. 11. Method according to claim 10, additionally comprising detection of the rotational movement of the movable part (360) by means of electromagnetic interaction between a second coil (476) and a second magnet (372) associated with said second coil. 12. Method according to either of claims 10 or 11, according to which the detected movement of the movable part (360) is used in a control system for controlling the wavelength of the light in the external cavity laser. 13. Method according to any one of claims 10 - 12, which method also comprises detection of the position of the movable part (360), which is used in said control system for controlling the wavelength of the light in the external cavity laser."
  ],
  "cpc": [
    "H01S 5/141",
    "H01S 5/143"
  ],
  "filing_date": "2001-08-17",
  "publication_date": "2002-02-28",
  "priority_date": "1999-02-19",
  "application_number": "US-93140301-A",
  "family_id": "26663511"
}