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US5805327A Expired / Lapsed US ⏱️ 0.0 years remaining

Reshaping device for optical short pulses

Assignee: KDDI Corp
•
Filing: 1996-05-21
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Granted: 1998-09-08
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Expires: 2016-05-21
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Abstract

Abstract There is disclosed a reshaping device for optical short pulses to effectively perform reshaping of and eliminate noise from an optical short pulse of a pulse width of pico second order less than a carrier life time. Input optical short pulses are applied to a saturable absorption element, while an assist light of a wavelength longer than that of the input optical signal pulses is also applied to the saturable absorption element to accelerate, by stimulated emission, recombination of excited electrons and holes produced in the saturable absorption element in response to the input optical signal pulses, so that the input optical signal pulses reshaped are derived from the saturable absorption element.

Inventors

  • 👤 Masashi Usami
  • 👤 Yuichi Matsushima
  • 👤 Munefumi Tsurusawa

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 12:21
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/35; G02F1/3511; G02F1/3513; H; H01; H01S; H01S3/00; H01S3/005; H01S3/0057

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 109 words
A reshaping device for optical short pulses, comprising: a semiconductor saturable absorption element; first injection means for injecting first input optical signal pulses of optical short pulses to said saturable absorption element; second injection means for injecting, to said saturable absorption element, second input light of a wavelength longer than that of said first input optical signal pulses to accelerate, by stimulated emission, recombination of excited electrons and holes produced in said saturable absorption element in response to said first input optical signal pulses; and output means for selectively outputting said first input optical signal pulses of optical short pulses reshaped and noise-eliminated from said semiconductor saturable absorption element.
Claim 2
Dependent Claim 109 words
A reshaping device for optical short pulses, comprising: a semiconductor saturable absorption element; first injection means for injecting first input optical signal pulses of optical short pulses to said saturable absorption element; second injection means for injecting, to said saturable absorption element, second input light of a wavelength longer than that of said first input optical signal pulses to accelerate, by stimulated emission, recombination of excited electrons and holes produced in said saturable absorption element in response to said first input optical signal pulses; and output means for selectively outputting said first input optical signal pulses of optical short pulses reshaped and noise-eliminated from said semiconductor saturable absorption element.
Claim 3
Dependent Claim 23 words
A reshaping device for optical short pulses according to claim 1, characterized in that said second input light comprises a continuous light wave.
Claim 4
Dependent Claim 21 words
A reshaping device for optical short pulses according to claim 1, characterized in that said second input light comprises optical pulses.
Claim 5
Dependent Claim 95 words
A reshaping device for optical short pulses according to claim 1, characterized in that a wavelength of said second input light is longer than that of said first input optical signal pulses, longer than that of light corresponding to an energy between respective quasi Fermi-levels of electrons and holes raised by electrons of a conduction band and holes of a valence band, which are produced in said semiconductor saturable absorption element in response to said first input optical signal pulses, and shorter than tat of an energy or a band edge determined by a bandgap.
Claim 6
Dependent Claim 52 words
A reshaping device for optical short pulses according to claim 1, characterized in that an intensity of said second input light is an intensity by which respective quasi Fermi-levels of excited electrons and holes produced in said semiconductor saturable absorption element in response to said first input optical signal pulses are lowered.
Claim 7
Dependent Claim 80 words
A reshaping device for optical short pulses according to claim 1, characterized in that said first injection means for injecting first input optical signal pulses and said second injection means for injecting second input light to said saturable absorption element are composed of an optical coupler, so that said first input optical signal pulses and said second input light are injected to said optical coupler and output light from said optical coupler is injected to said semiconductor saturable absorption element.
Claim 8
Dependent Claim 46 words
A reshaping device for optical short pulses according to claim 1, characterized in that said semiconductor saturable absorption element comprises a surface emitting semiconductor saturable absorptionn element, so that said first input optical signal pulses and said second input light are injected from two directions thereof.
Claim 9
Dependent Claim 71 words
A reshaping device for optical short pulses according to claim 1, characterized in that said output means for selectively outputting said first input optical signal pulses of optical short pulses reshaped and noise-eliminated from said semiconductor saturable absorption element comprises an optical fiber for separately deriving said first input optical signal pulses from said first input optical signal pulses and said second input light outputted from said semiconductor saturable absorption element.
Claim 10
Dependent Claim 34 words
A reshaping device for optical short pulses according to any one of claims 1 to 8, characterized in that means for injecting a direct current to said semiconductor saturable absorption element is further provided.

References Cited (Backward Citations)

US4209690A Cited
US5175739A Cited
JPH0545692A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-09-07 2002-03-09 2002-09-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-09-07 2006-03-09 2006-09-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-09-07 2010-03-09 2010-09-08 $7700.00 Window Closed / Lapsed

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