Patent EP0060033A1 successfully refreshed from Google Patents.
EP0060033A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Improvements in or relating to laser light sources
Assignee: British Telecommunications PLC
•
Filing: 1982-02-12
•
Granted: —
•
Expires: 2002-02-12
Abstract
Abstract A light source comprises a first laser 10 and a second laser 11 which is arranged so that light from the first laser can be injected into the second. The bias to the lasers is controlled so that the first laser acts as an oscillator and the second laser as a modulator, the output from the modulator being a single longitudinal mode. A low frequency signal is applied to the first laser 10 and detected in the output of the second laser 11. A phase sensitive detector 18 is responsive to the sensed signal to provide a feedback signal for the second laser 11 such that the cavity modes of the two lasers are aligned automatically.
Inventors
- 👤 Derek John Malyon
- 👤 David William Smith
- 👤 Ronald William Berry
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 14:42
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/50; H04B10/501; H04B10/503; H04B10/504; H01; H01S; H01S5/00; H01S5/40; H01S5/4006; H01S5/06; H01S5/062; H01S5/06209; H01S5/06213; H01S5/068; H01S5/0683; H01S5/0687
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
A light source comprising a first laser (10), a second laser (11) arranged such that light from the first laser can be injected into said second laser to stimulate said second laser (11), and means for controlling said lasers such that the optical output of the source is a single longitudinal mode, characterised in that the control means includes means (22) for applying a varying signal to one of said lasers, means (21) for sensing the varying signal at or in the output of the second laser (11), and means (18, 16) responsive to the sensed signal for controlling one or both of the lasers such that their cavity modes are aligned.
Claim 2
Dependent Claim
112 words
A light source comprising a first laser (10), a second laser (11) arranged such that light from the first laser can be injected into said second laser to stimulate said second laser (11), and means for controlling said lasers such that the optical output of the source is a single longitudinal mode, characterised in that the control means includes means (22) for applying a varying signal to one of said lasers, means (21) for sensing the varying signal at or in the output of the second laser (11), and means (18, 16) responsive to the sensed signal for controlling one or both of the lasers such that their cavity modes are aligned.
Claim 3
Dependent Claim
73 words
A light source as claimed in claim 1 characterised in that the control means includes means (22) for injecting a low frequency current on the bias of the first laser (10), a photoelectric detector (21) for sensing the optical output of the second laser (11), and a phase sensitive detector (18) connected to said photoelectric detector and arranged to provide a feedback signal for controlling the bias or temperature of the second laser.
Claim 4
Dependent Claim
43 words
A light source as claimed in claim 1 or claim 2 characterised in that the lasers (10, 11) have a different cavity Q whereby the optical power injected into the second laser (11) can be selected such that the vernier mode is suppressed.
Claim 5
Dependent Claim
44 words
A light source as claimed in any preceding claim characterised in that the first laser (10) is operated in a stable continuous wave single mode and the control means for the first laser includes a wavelength sensed feedback (12) for controlling power and wavelength.
Claim 6
Dependent Claim
20 words
A light source as claimed in claim 4 characterised in that the control means also includes a Peltier unit (15).
Claim 7
Dependent Claim
26 words
A light source as claimed in any preceding claim characterised in that the control means for the second laser includes a temperature bias tuning unit (16).
Claim 8
Dependent Claim
34 words
A light source as claimed in any preceding claim characterised in that the first laser (10) is a channelled substrate planar device and the second laser (11) is a multi-longitudinal moded gain guided device.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.