US4504976A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for regulating a laser diode
Assignee: Societe Anonyme de Telecommunications SAT
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Filing: 1983-05-03
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Granted: 1985-03-12
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Expires: 2003-05-03
Abstract
Abstract The present invention relates to a device for regulating a laser diode, which comprises a generator of a pilot frequency signal modulated by a reference signal forming part of a composite signal to be emitted and a gain regulator of the composite signal. The regulation circuit comprises a photodiode whose output signal is demodulated by means of the pilot frequency signal, filtered then detected before being applied to the gain regulator.
Inventors
- 👤 Didier Beaudet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:42
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/50; H04B10/501; H04B10/503; H04B10/504; H04B10/564
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
194 words
Apparatus for regulating emissions from a laser diode comprising: a luminous energy-emitting laser diode; a control photodiode for collecting luminous energy emitted by said laser diode and providing a photodiode signal as a function of the collected energy; feedback means responsive to said photodiode signal for controlling the energy emitted by said laser diode; generator means for providing a pilot signal at a pilot frequency; modulation means for modulating said pilot signal with a digital pulse train to provide a modulated pilot signal; coupling means for combining said modulated pilot signal with a composite signal to provide a first signal as a function of the combined modulated pilot signal and the composite signal; automatic gain control means responsive to application of a gain control signal thereto for automatically regulating the amplitude of said first signal; means for modulating the luminous energy emitted by said laser diode as a function of said amplitude-regulated first signal; demodulator means for demodulating said photodiode signal with said pilot signal to provide a demodulated signal; and filtering and detection means for filtering and detecting said demodulated signal to provide said control signal applied to said automatic gain control means.
Claim 2
Dependent Claim
194 words
Apparatus for regulating emissions from a laser diode comprising: a luminous energy-emitting laser diode; a control photodiode for collecting luminous energy emitted by said laser diode and providing a photodiode signal as a function of the collected energy; feedback means responsive to said photodiode signal for controlling the energy emitted by said laser diode; generator means for providing a pilot signal at a pilot frequency; modulation means for modulating said pilot signal with a digital pulse train to provide a modulated pilot signal; coupling means for combining said modulated pilot signal with a composite signal to provide a first signal as a function of the combined modulated pilot signal and the composite signal; automatic gain control means responsive to application of a gain control signal thereto for automatically regulating the amplitude of said first signal; means for modulating the luminous energy emitted by said laser diode as a function of said amplitude-regulated first signal; demodulator means for demodulating said photodiode signal with said pilot signal to provide a demodulated signal; and filtering and detection means for filtering and detecting said demodulated signal to provide said control signal applied to said automatic gain control means.
Claim 3
Dependent Claim
28 words
The apparatus according to claim 1 wherein said coupling means is a signal summing circuit for summing the amplitudes of said modulated pilot signal and said composite signal.
Claim 4
Dependent Claim
28 words
The apparatus according to claim 1 further comprising amplifier means for amplifying the amplitude-regulated first signal prior to modulation thereby of the energy emitted by said laser diode.
References Cited (Backward Citations)
US4211929A
Cited
GB2025121A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-03-11 | 1988-09-10 | 1989-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-03-11 | 1992-09-10 | 1993-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-03-11 | 1996-09-10 | 1997-03-12 | $7700.00 | Window Closed / Lapsed |