HIGH-EFFICIENCY DIRECT FREQUENCY MODULATION OF EXTERNAL-RESONATOR SEMICONDUCTOR LASER DIODE

外谐振半导体激光二极管的高效直接频率调制

• 批准号: 61550276
• 负责人: SHINOHARA Shigenobu
• 金额: $ 1.34万
• 依托单位: SHIZUOKA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-61550276/
• 关键词: EXTERNAL-RESONATOR SEMICONDUCTOR LASER; SYNCHRONOUS FM MODULATION; AUTOMATIC PHASE CONTROL; PHASE STABILIZATION; HIGH-EFFICIENCY MODULATION; 戻り光位相安定化; 半導体レーザ; 直接周波数変調; FM雑音; FM変調効率; 外部共振器

Described are a theory and experimental verification of improving the FM modulation efficiency together with the FM noise reduction of an external-resonator semiconductor laser diode (LD), by means of synchronously modulating LD drive current with phase of the returned light, reflected from the mirror comprising the external resonator.(1) Experiment on synchronous FM modulation with 110kHz sinusoidal wave : In case of modulation without automatic phase control(APC) for the returned light, FM noise has been reduced approximately proportioning to 1/(1+<xi>)^2 as feedback parameter <xi> is increased to 5, except for<xi> 1; the reduction reached 1/27 times the value of solitary LD. While modulation efficiency for the synchronous FM increased monotonously with increase of amplitude Lm of modulation of the external-resonator length L(=18cm). And when <DELTA>Lm =(<lambda>/2) (<DELTA>fm/fex), that increased to the value for solitary LD, 1.6 GHz/mA, which is (1+ <xi>) times conventional direct … More FM modulation efficiency. By further increase of the <DELTA>Lm, FM modulation efficiency increased as high as 13 GHz/mA, which is 8 times the value for solitary LD; where <lambda> is light wavelength, <DELTA>fm maximum frequency deviation for solitary LD modulated with sinusoidal current, and fex external resonator frequency. On the other hand,in case of synchronous modulation with APC, FM noise reduction was 2.4 dB, and FM modulation efficiency improvement 5 times, resulting 7.9 GHz/mA, when <xi> was set 0.8. Furthermore, by cooperating of the APC for 40 minutes, phase fluctuation of the returned light has been suppressed by about a twentieth to 14 degrees, which stabilized FM signal amplitude variation within 0.2 dB, and FM noise variation within 0.8 dB.(2) Experiment on synchronous FM modulation with 11 MHz sinusoidal wave: FM noise reduction and FM modulation efficiency improvement are also achieved by modulating phase of the returned light using LiNbO_3 optical phase modulator at 11 MHz. Less

本文描述了通过同步调制半导体激光二极管(LD)的驱动电流和从包括外谐振腔的反射镜反射的回光的相位来提高调频调制效率和降低调频噪声的理论和实验验证。(1)110 kHz正弦波同步调频实验：在没有对返回光进行自动相位控制(APC)的情况下，作为反馈参数，调频噪声降至约1/(1+lt；xi&gt；)^2，除&lt；xi&gt；1；缩小率为单侧LD的1/27倍。而同步调频的调制效率随着外腔长度L(=18 cm)调制幅度Lm的增加而单调增加。当Lm=(Lt；Lambda；/2)(&lt；Delta；Fm/Fex)时，增加到孤立LD的值1.6 GHz/mA，这是传统直接…的(1+1)倍更高的调频调制效率。通过进一步增加&lt；Delta&>Lm，调频调制效率高达13 GHz/mA，是孤立LD的8倍；其中&lt；lambda&gt；是光波长，对于正弦电流调制的孤立LD和Fex外谐振器频率，&lt；Delta&>FM的最大频偏。另一方面，在与APC同步调制的情况下，当&lt；xi&gt；设置为0.8时，调频噪声降低了2.4分贝，调频调制效率提高了5倍，结果是7.9 GHz/mA。此外，通过与APC配合40分钟，返回光的相位起伏被抑制了约20~14度，从而将调频信号的幅度变化稳定在0.2分贝以内，调频噪声的变化稳定在0.8分贝以内。(2)11 MHz正弦波同步调频实验：利用11 MHz的LiNbO_3光学相位调制器对返回光进行相位调制，也实现了调频噪声的降低和调频调制效率的提高。较少

项目成果

SHIGENOBU SHINOHARA,MASATOSHI KANEMATSU,HIROFUMI YOSHIDA,AND MASAO SUMI: "HIGH-EFFICIENCY SYNCHRONOUS FM MODULATION OF EXTERNAL CAVITY SEMICONDUCTOR LASER DIODE" IEICE,TECHNICAL REPORT. CS87-97. 39-43 (1987)

SHIGENOBU Shinohara、Masatoshi KANEMATSU、HIROFUMI YOSHIDA 和 MASAO SUMI：“外腔半导体激光二极管的高效同步 FM 调制”IEICE，技术报告。