Mid-range Frequency-modulated Continuous-wave Reflectometry Using A Narrow-linewidth Laser Diode With Linearized Optical Frequency Sweep

1997 ◽  
Author(s):  
K. Iiyama ◽  
Y. Itou
Keyword(s):  
Laser Diode ◽  
Continuous Wave ◽  
Optical Frequency ◽  
Narrow Linewidth ◽  
Frequency Sweep

scholarly journals THz Signal Generator Using a Single DFB Laser Diode and the Unbalanced Optical Fiber Interferometer

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4862
Author(s):  
Blaž Pongrac ◽  
Denis Đonlagic ◽  
Matej Njegovec ◽  
Dušan Gleich
Keyword(s):  
Optical Fiber ◽  
Laser Diode ◽  
Optical Signal ◽  
Optical Path Difference ◽  
Sweep Rate ◽  
Path Difference ◽  
Optical Path ◽  
Signal Generator ◽  
Optical Frequency ◽  
Frequency Sweep

This paper presents a frequency-modulated optical signal generator in the THz band. The proposed method is based on a fast optical frequency sweep of a single narrowband laser diode used together with an optical fiber interferometer. The optical frequency sweep using a single laser diode is achieved by generating short current pulses with a high amplitude, which are driving the laser diode. Theoretical analysis showed that the modulation frequency could be changed by the optical path difference of the interferometer or optical frequency sweep rate of a laser diode. The efficiency of the optical signal generator with Michelson and Fabry–Perot interferometers is theoretically analyzed and experimentally evaluated for three different scenarios. Interferometers with different optical path differences and a fixed optical frequency sweep rate were used in the first scenario. Different optical frequency sweep rates and fixed optical path differences of the interferometers were used in the second scenario. This paper presents a method for optical chirp generation using a programmable current pulse waveform, which drives a laser diode to achieve nonlinear optical sweep with a fixed optical path difference of the interferometer. The experimental results showed that the proposed signals could be generated within a microwave (1–30 GHz) and THz band (0.1–0.3 THz).

scholarly journals QAM Transmission over RoF Using Fabry Perot Laser Diode and Continuous Wave Laser Diode

2019 ◽  
Vol 8 (12) ◽  
pp. 531-535
Keyword(s):  
Millimeter Wave ◽  
Laser Diode ◽  
Amplitude Modulation ◽  
Continuous Wave ◽  
Frequency Comb ◽  
Optical Frequency ◽  
Continuous Wave Laser ◽  
Eye Diagram ◽  
Fabry Perot ◽  
Wave Laser

This paper introduces the Quadrature Amplitude Modulation (QAM) Radio over Fiber (RoF) framework dependent on Optical Frequency Comb (OFC) generation utilizing Fabry-Perot Laser Diode (FPLD) and Continuous Wave Laser Diode (CWLD). In this, optical Millimeter-Wave (MMW) can be created ether utilizing ease FPLD with an outside optical infusion or a continuous wave laser diode. At the base, optical MMW can be recognized by utilizing photodetector in the two transmissions. The experimental results are explained by using the constellation and eye diagram.

scholarly journals Linearizing optical frequency-sweep of a laser diode for FMCW reflectometry

1996 ◽  
Vol 14 (2) ◽  
pp. 173-178 ◽  
Author(s):  
K. Iiyama ◽  
Lu-Tang Wang ◽  
Ken-Ichi Hayashi
Keyword(s):  
Laser Diode ◽  
Optical Frequency ◽  
Frequency Sweep

scholarly journals Coherent control of acoustic phonons in a silica fiber using a multi-GHz optical frequency comb

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mamoru Endo ◽  
Shota Kimura ◽  
Shuntaro Tani ◽  
Yohei Kobayashi
Keyword(s):  
Coherent Control ◽  
Continuous Wave ◽  
Frequency Comb ◽  
Effective Interaction ◽  
Interaction Strength ◽  
Single Mode ◽  
Optical Frequency Comb ◽  
Material Structure ◽  
Optical Frequency ◽  
Acoustic Phonons

AbstractMulti-gigahertz mechanical vibrations that stem from interactions between light fields and matter—known as acoustic phonons—have long been a subject of research. In recent years, specially designed functional devices have been developed to enhance the strength of the light-matter interactions because excitation of acoustic phonons using a continuous-wave laser alone is insufficient. However, the strength of the interaction cannot be controlled appropriately or instantly using these structurally-dependent enhancements. Here we show a technique to control the effective interaction strength that does not operate via the material structure in the spatial domain; instead, the method operates through the structure of the light in the time domain. The effective excitation and coherent control of acoustic phonons in a single-mode fiber using an optical frequency comb that is performed by tailoring the optical pulse train. This work represents an important step towards comb-matter interactions.

scholarly journals Spectral Broadening in a Continuously Pumped Singly Resonant Second-Harmonic Cavity

2021 ◽  
Vol 11 (15) ◽  
pp. 7122
Author(s):  
Simona Mosca ◽  
Tobias Hansson ◽  
Maria Parisi
Keyword(s):  
Continuous Wave ◽  
Frequency Comb ◽  
Second Harmonic ◽  
Input Power ◽  
Second Order ◽  
Optical Frequency ◽  
Frequency Combs ◽  
Research Areas ◽  
Mixed Regime ◽  
Wide Range

Optical frequency comb synthesizers with a wide spectral range are an essential tool for many research areas such as spectroscopy, precision metrology, optical communication, and sensing. Recent studies have demonstrated the direct generation of frequency combs, via second-order processes, that are centered on two different spectral regions separated by an octave. Here, we present the capability of optical quadratic frequency combs for broad-bandwidth spectral emission in unexplored regimes. We consider comb formation under phase-matched conditions in a continuous-wave pumped singly resonant second-harmonic cavity, with large intracavity power and control of the detuning over several cavity line widths. The spectral analysis reveals quite distinctive sidebands that arise far away from the pump, singularly or in a mixed regime together with narrowband frequency combs. Notably, by increasing the input power, the optical frequency lines evolve into widely spaced frequency clusters, and at maximum power, they appear in a wavelength range spanning up to 100 nm. The obtained results demonstrate the power of second-order nonlinearities for direct comb production within a wide range of pump wavelengths.

The Ka-band 10-kW continuous wave gyrotron with wide-band fast frequency sweep

2012 ◽  
Vol 83 (7) ◽  
pp. 074706 ◽  
Author(s):  
M. Glyavin ◽  
A. Luchinin ◽  
M. Morozkin
Keyword(s):  
Continuous Wave ◽  
Wide Band ◽  
Frequency Sweep ◽  
Ka Band
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