Optical short pulse generating device

• US 5,434,693 A
• Filed: 03/16/1994
• Issued: 07/18/1995
• Est. Priority Date: 03/25/1993
• Status: Expired due to Term

• Current Assignee: KDDI Corporation
• Original Assignee: Kokusai Densin Denwa Kabushiki Kaisha
• Inventors: Tanaka, Hideaki, Suzuki, Masatoshi, Takagi, Satoru, Matsushima, Yuichi
• Primary Examiner(s): Moore, David K.
• Assistant Examiner(s): NEGASH, KINFE MICHAEL
• Application Number:
  US08/213,928
• Time in Patent Office: 489 Days
• Field of Search: 359/140, 359/160, 359/162, 359/180-181, 359/183, 372/26, 372/38, 385/2, 385/3, 385/8
• US Class Current: 398/192
• CPC Class Codes: G02F 1/0121 Operation of devices; Circuit arrangements, not otherwise provided for in this subclass
• CPC Class Codes: G02F 1/015 based on semiconductor elements having potential barriers, e.g. having a PN or PIN junction G02F1/03 takes precedence
• CPC Class Codes: G02F 1/0157 using electro-absorption effects, e.g. Franz-Keldysh [FK] effect or quantum confined stark effect [QCSE]
• CPC Class Codes: G02F 2203/26 Pulse shaping; Apparatus or methods therefor
• CPC Class Codes: G02F 2203/54 Optical pulse train (comb) synthesizer
• CPC Class Codes: H04B 10/50 Transmitters

Abstract

An optical short pulse generating device is disclosed, in which semiconductor laser light of a fixed intensity is launched into a first semiconductor electroabsorption optical modulator which is driven by a 0V or forward bias voltage and a sinusoidal voltage, and the output light from the first optical modulator is launched into a second electroabsorption optical modulator to which is applied a bias voltage and a sinusoidal voltage having delayed from the said sinusoidal voltage for a period of time corresponding to the phase reversal thereof, whereby it is possible to generate optical short pulses of a repetition frequency twice higher than the oscillation frequency of a sinusoidal voltage generator.

Claims

1. An optical pulse generating device, comprising:

a continuously oscillating semiconductor laser;

a first semiconductor electroabsorption optical modulator for performing intensity modulation of the output light of said semiconductor laser;

a second electroabsorption optical modulator for performing intensity modulation of the output light from said first electroabsorption optical modulator;

a sinusoidal voltage generator for generating a sinusoidal voltage for driving said first and second electroabsorption optical modulators;

a DC voltage generator for applying a DC bias voltage to said first and second electroabsorption optical modulators; and

a delay circuit inserted between said second electroabsorption optical modulator and said sinusoidal voltage generator for delaying said sinusoidal voltage from said sinusoidal voltage generator for a period of time corresponding to its phase reversal.

2. An optical pulse generator device according to claim 1, in which said DC voltage generator generates the DC bias voltage of zero volt.

3. An optical pulse generator device according to claim 1, in which said DC voltage generator generates a forward DC bias voltage as the DC bias voltage with respect to said modulators.