© 2026 Aqora Quantum S.A.S.

Terms Privacy Legal Notice

Electronics and Communications in Japan (Part II Electronics)

Negative amplification of optical signal derived from negative nonlinear absorption effect in Er-doped fibers

Yoshinobu Maeda, Takao Sakakibara, Masatoshi Migitaka

Published Jul 1, 1997• 0 citations

Abstract

A reversion of optical signal is observed in a 470 ppm Er-doped fiber with more than 2 m in length, and the negative nonlinear absorption (NNA) effect is confirmed. The negative amplification, which is the ratio of modulation indexes between the transmitted and input lights, is confirmed, and the maximum negative amplification of −2.9 is obtained. It is found from the measurements the room (300 K) and liquid nitrogen temperatures (77 K) that the negative effect is larger at room temperature than at liquid nitrogen temperature. The NNA effect is observed in the wavelength range from 784 to 792 nm and with incident laser power intensities ranging from 3 mW/cm2 to 14 mW/cm2. The NNA effect is observed for the modulation frequency up to 1 MHz, and for high frequency the transmitted waveform becomes asymmetric. The polarization dependence of the effect is also confirmed. The mechanism of the NNA effect is considered mainly due to the enhanced absorption caused by the spontaneous emission in the excited three-level system. Since the emission light can be propagated in the fiber with very low loss, the NNA effect can be effectively generated causing the negative amplification of the optical signal. © 1998 Scripta Technica. Electron Comm Jpn Pt 2, 80(7): 8–17, 1997

DOI: 10.1002/(sici)1520-6432(199707)80:7<8::aid-ecjb2>3.0.co;2-h

Related papers

Optical signal inversion phenomena due to negative nonlinear absorption effect

Yoshinobu Maeda, Seiichi Ikeda, Takao Sakakibara +1 more

A negative input-output characteristic was obtained in an erbium-doped yttrium aluminum garnet crystal which has multiple-level energy structure: absorption can occur between a ground level and an excited level (4I−4I) and between two other excited levels (4I−2H) in Er3+. It occurred at a wavelength between 786.6 and 788.4 nm by variation of the incident laser intensity in the intensity range of 60 nW/cm2 to 100 W/cm2. It is considered that an enhanced absorption occurs due to the excited-state absorption from 4I to 2H, its spectra matching the wavelength dependence of the incident laser In addition, optical signal inverter phenomenon was observed using a laser diode modulated at 10 MHz. By considering multiple excited-state absorption in detail, active functions such as an optical signal inverter could be derived from the negative nonlinear absorption effect. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(4): 74–80, 1997

Electrical Engineering in Japan•Sep 1, 1997•0 citations

All-optical inverter derived from negative nonlinear absorption effect

Toshikazu Yamada, Yoshinobu Maeda

Dependence of the negative nonlinear absorption effect (NNA effect) on modulation frequency was investigated in an erbium-doped lutetium aluminum garnet (Er:LuAG) crystal at the wavelength of 787.8 nm. When the intensity of the incident laser irradiated on Er:LuAG and Er:YAG crystals was wavy, those crystals were observed NNA effect that the transmitted laser intensity shows opposite phase of the incident laser at the wavelength of about 788 nm. The transmitted waveforms changed to the opposite phase of the incident waveform for modulation frequencies up to 1 GHz. For 1 GHz, the peak of the reversed-phase waveform was shifted by approximately 250 ps.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Sep 20, 1999•0 citations

All-Optical Switch Derived from the Negative Nonlinear Absorption Effect in Erbium-Doped Fibers

Yoshinobu Maeda, Masatoshi Migitaka

An all-optical switch which has a negative amplification of the optical signal was demonstrated in an erbium-doped fiber. The dependence of the negative nonlinear absorption effect on the modulation degree of the incident laser was investigated and we obtained the negative amplification degree of -3 for a fiber length of 6 m at room temperature. It has been confirmed that the mechanism of the effect can be explained by calculating the rate equations based on an analytical model for a five-level system of the Er3+ ion. It is suggested that the effect was due to stimulated emission from the 4 S 3/2 level to the 4 I 13/2 level.

Japanese Journal of Applied Physics•Nov 1, 1997•8 citations

Negative nonlinear absorption effect in erbium-doped fibers

Yoshinobu Maeda, Takao Sakakibara, M. Migitaka

The dependence of the negative nonlinear absorption effect on both modulation degree and modulation frequency of an incident laser was investigated in erbium-doped fibers at 77 K. Negative input-output characteristics were obtained at modulation frequencies of 10 to 250 kHz for fiber lengths above 2 m. The maximum ratio of the transmitted modulation degree to the incident one was approximately -2 for a fiber length of 4 m. It is suggested that emissions induced in the fiber can contribute to the negative nonlinear absorption effect because they propagate with low loss.

Conference on Lasers and Electro-Optics•Aug 24, 2005•0 citations

Negative Nonlinear Absorption Effect in Erbium Doped Fibers

Yoshinobu Maeda, Takao Sakakibara, Masatoshi Migitaka

The dependence of the negative nonlinear absorption effect on both modulation degree and modulation frequency of an incident laser was investigated in erbium-doped fibers at 77 K. Negative input-output characteristics were obtained at modulation frequencies of 10 to 250 kHz for fiber lengths above 2 m. The maximum ratio of the transmitted modulation degree to the incident one was approximately -2 for a fiber length of 4 m. It is suggested that emissions induced in the fiber can contribute to the negative nonlinear absorption effect because they propagate with low loss.

Japanese Journal of Applied Physics•Mar 1, 1997•15 citations

Negative nonlinear absorption effect in erbium-doped fibers

Yoshinobu Maeda, Takao Sakakibara, Masatoshi Migitaka

The dependence of the negative nonlinear absorption effect on both modulation degree and modulation frequency of an incident laser was investigated in erbium-doped fibers at 77 K. Negative input-output characteristics were obtained at modulation frequencies of 10 to 250 kHz for fiber lengths above 2 m. The maximum ratio of the transmitted modulation degree to the incident one was approximately -2 for a fiber length of 4 m. It is suggested that emissions induced in the fiber can contribute to the negative nonlinear absorption effect because they propagate with low loss.

IEEE Lasers and Electro-Optics Society Annual Meeting (LEOS)•Jan 1, 1997•0 citations

A reversion of optical signal is observed in a 470 ppm Er-doped fiber with more than 2 m in length, and the negative nonlinear absorption (NNA) effect is confirmed. The negative amplification, which is the ratio of modulation indexes between the transmitted and input lights, is confirmed, and the maximum negative amplification of −2.9 is obtained. It is found from the measurements the room (300 K) and liquid nitrogen temperatures (77 K) that the negative effect is larger at room temperature than at liquid nitrogen temperature. The NNA effect is observed in the wavelength range from 784 to 792 nm and with incident laser power intensities ranging from 3 mW/cm2 to 14 mW/cm2. The NNA effect is observed for the modulation frequency up to 1 MHz, and for high frequency the transmitted waveform becomes asymmetric. The polarization dependence of the effect is also confirmed. The mechanism of the NNA effect is considered mainly due to the enhanced absorption caused by the spontaneous emission in the excited three-level system. Since the emission light can be propagated in the fiber with very low loss, the NNA effect can be effectively generated causing the negative amplification of the optical signal. © 1998 Scripta Technica. Electron Comm Jpn Pt 2, 80(7): 8–17, 1997

A negative input-output characteristic was obtained in an erbium-doped yttrium aluminum garnet crystal which has multiple-level energy structure: absorption can occur between a ground level and an excited level (4I−4I) and between two other excited levels (4I−2H) in Er3+. It occurred at a wavelength between 786.6 and 788.4 nm by variation of the incident laser intensity in the intensity range of 60 nW/cm2 to 100 W/cm2. It is considered that an enhanced absorption occurs due to the excited-state absorption from 4I to 2H, its spectra matching the wavelength dependence of the incident laser In addition, optical signal inverter phenomenon was observed using a laser diode modulated at 10 MHz. By considering multiple excited-state absorption in detail, active functions such as an optical signal inverter could be derived from the negative nonlinear absorption effect. © 1997 Scripta Technica, Inc. Electr Eng Jpn, 120(4): 74–80, 1997

Dependence of the negative nonlinear absorption effect (NNA effect) on modulation frequency was investigated in an erbium-doped lutetium aluminum garnet (Er:LuAG) crystal at the wavelength of 787.8 nm. When the intensity of the incident laser irradiated on Er:LuAG and Er:YAG crystals was wavy, those crystals were observed NNA effect that the transmitted laser intensity shows opposite phase of the incident laser at the wavelength of about 788 nm. The transmitted waveforms changed to the opposite phase of the incident waveform for modulation frequencies up to 1 GHz. For 1 GHz, the peak of the reversed-phase waveform was shifted by approximately 250 ps.

An all-optical switch which has a negative amplification of the optical signal was demonstrated in an erbium-doped fiber. The dependence of the negative nonlinear absorption effect on the modulation degree of the incident laser was investigated and we obtained the negative amplification degree of -3 for a fiber length of 6 m at room temperature. It has been confirmed that the mechanism of the effect can be explained by calculating the rate equations based on an analytical model for a five-level system of the Er3+ ion. It is suggested that the effect was due to stimulated emission from the 4 S 3/2 level to the 4 I 13/2 level.

The dependence of the negative nonlinear absorption effect on both modulation degree and modulation frequency of an incident laser was investigated in erbium-doped fibers at 77 K. Negative input-output characteristics were obtained at modulation frequencies of 10 to 250 kHz for fiber lengths above 2 m. The maximum ratio of the transmitted modulation degree to the incident one was approximately -2 for a fiber length of 4 m. It is suggested that emissions induced in the fiber can contribute to the negative nonlinear absorption effect because they propagate with low loss.

The dependence of the negative nonlinear absorption effect on both modulation degree and modulation frequency of an incident laser was investigated in erbium-doped fibers at 77 K. Negative input-output characteristics were obtained at modulation frequencies of 10 to 250 kHz for fiber lengths above 2 m. The maximum ratio of the transmitted modulation degree to the incident one was approximately -2 for a fiber length of 4 m. It is suggested that emissions induced in the fiber can contribute to the negative nonlinear absorption effect because they propagate with low loss.

The dependence of the negative nonlinear absorption effect on both modulation degree and modulation frequency of an incident laser was investigated in erbium-doped fibers at 77 K. Negative input-output characteristics were obtained at modulation frequencies of 10 to 250 kHz for fiber lengths above 2 m. The maximum ratio of the transmitted modulation degree to the incident one was approximately -2 for a fiber length of 4 m. It is suggested that emissions induced in the fiber can contribute to the negative nonlinear absorption effect because they propagate with low loss.