Patent EP0683552A2 successfully refreshed from Google Patents.
EP0683552A2
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EP
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Method and device for controlling the peak power of a laser transmitter in discontinuous optical transmission systems
Assignee: OTC Optical Technologies Center SRL
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Filing: 1995-05-20
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Granted: —
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Expires: 2015-05-20
Abstract
Abstract The device controls the peak power by acting on the threshold current of the transmitter. A sample and hold circuit (SH) samples the current supplied by the monitoring detector associated with the transmitter, and a processing unit (MP) obtains an actual value of the peak power as an average of the values associated with a certain number of samples of the monitoring current and, in case of divergence between the actual value and a desired value, obtains a correct value for the threshold current.
Inventors
- 👤 Paolo Solina
- 👤 Maurizio Valvo
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 17:45
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/50; H04B10/564; H01; H01S; H01S5/00; H01S5/06; H01S5/068; H01S5/0683; H01S5/06832; H04B10/501; H04B10/503; H04B10/504; H01S5/06812
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
143 words
Method of controlling the peak power of a laser transmitter in a discontinuous transmission system, wherein the laser (L) is modulated by a modulating current resulting from the combination of a threshold current and a current due to a data signal and wherein a fraction of the output signal of the laser is taken and converted into a monitoring current, characterized in that said monitoring current is sampled, an actual value of the peak power is obtained as an average computed over a predetermined number of samples of monitoring current, the actual value of the peak power so obtained is compared with a desired value of the peak power and an updated value for the laser threshold current is obtained from the difference, if any, between the reference value and the actual value, said updated value being such as to compensate said difference.
Claim 2
Dependent Claim
27 words
Method as claimed in claim 1, characterized in that, before sampling, the monitoring current is rectified and the rectified current is memorized in a memory capacitor (C).
Claim 3
Dependent Claim
22 words
Method as claimed in claim 1 or 2, characterized in that the samples of the monitoring current are converted into digital form.
Claim 4
Dependent Claim
56 words
Method according to any of the previous claims, characterized in that the discontinuous transmission is a packet transmission where each packet starts with a unique word comprising an initial group of bits with a preset logic value, and in that the sampling is performed in correspondence with said word, after the last bit of said group.
Claim 5
Dependent Claim
31 words
Method as claimed in claim 4 if referred to claim 2, characterized in that the monitoring current is memorized for a period of time corresponding with the duration of a packet.
Claim 6
Dependent Claim
178 words
Device for controlling the peak power of a laser transmitter (TL) in a discontinuous transmission system, wherein the transmitter (TL) is modulated by a current resulting from the combination of a threshold current, supplied by a threshold current generator (GS1) and of a current due to a data signal, supplied by a data current generator (GD), and is associated with a monitoring detector (RV) which takes a fraction of the output signal from the laser and converts it into a monitoring current, characterized in that it comprises: - a circuit (SH) for sampling the monitoring current; and - a processing unit (UE) arranged for: obtaining the actual value of the peak power as an average over a predetermined number of samples of the monitoring current; comparing the actual value of the peak power thus found with a desired value of that power; obtaining from the difference between the desired value and the actual value an updated value for the laser threshold current, such as to compensate said difference; supplying the updated value to the threshold current generator (GS1).
Claim 7
Dependent Claim
21 words
Device as claimed in claim 6, characterized in that it includes a memory capacitor (C) upstream of the sampling circuit (SH).
Claim 8
Dependent Claim
40 words
Device as claimed in claim 6 or 7, characterized in that the processing unit (UE) is initialized with a value of the threshold current corresponding with the nominal threshold current of the transmitter (TL) at the beginning of its life.
Claim 9
Dependent Claim
82 words
Device according to any of claims 6 to 8, characterized in that the laser transmitter (TL) is a subscriber's transmitter of an optical communication network in TDMA technique, where packets are transmitted that start with a word comprising an initial group of bits with a preset logic value, and in that the sampling circuit (SH) is enabled to sample the monitoring current supplied by said detector (RV) in response to the portion of the starting word which follows said group of bits.
Claim 10
Dependent Claim
27 words
Device as claimed in claim 9, characterized in that the optical communication network in TDMA technique is a passive optical network and the packets are ATM cells.
References Cited (Backward Citations)
No citation records indexed.
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