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A Time Difference Method for Measurement of Phase Shift between Distributed Feedback Laser Diode (DFB-LD) Output Wavelength and Intensity.

Liu Y, Chang J, Lian J, Liu Z, Wang Q, Zhu C - Sensors (Basel) (2015)

Bottom Line: This approach takes advantage of asymmetric absorption positions at the same wavelength during wavelength increase and decrease tuning processes in the intensity-time curve by current modulation.The phase shifts at modulation frequencies ranging from 50 Hz to 50 kHz were measured with a resolution of 0.001π.As the modulation frequency increased the shift value increased with a slowed growth rate.

View Article: PubMed Central - PubMed

Affiliation: School of Information Science and Engineering, Shandong University, Jinan 250100, China. Liuyongning1990@163.com.

ABSTRACT
A time difference method to conveniently measure the phase shift between output wavelength and intensity of distributed feedback laser diodes (DFB-LDs) was proposed. This approach takes advantage of asymmetric absorption positions at the same wavelength during wavelength increase and decrease tuning processes in the intensity-time curve by current modulation. For its practical implementation, a measurement example of phase shift was demonstrated by measuring a time difference between the first time and the second time attendances of the same gas absorption line in the intensity-time curve during one sine or triangle modulation circle. The phase shifts at modulation frequencies ranging from 50 Hz to 50 kHz were measured with a resolution of 0.001π. As the modulation frequency increased the shift value increased with a slowed growth rate.

No MeSH data available.


Related in: MedlinePlus

Transmitted intensity-time curves of sine and triangle modulation cases respectively at 50 Hz, 100 Hz and 500 Hz, specifically, (a) Sine wave modulation at 50 Hz; (b) Sine wave modulation at 100 Hz; (c) Sine wave modulation at 500 Hz; (d) Triangle wave modulation at 50 Hz; (e) Triangle wave modulation at 100 Hz; (f) Triangle wave modulation at 500 Hz.
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sensors-15-16153-f003: Transmitted intensity-time curves of sine and triangle modulation cases respectively at 50 Hz, 100 Hz and 500 Hz, specifically, (a) Sine wave modulation at 50 Hz; (b) Sine wave modulation at 100 Hz; (c) Sine wave modulation at 500 Hz; (d) Triangle wave modulation at 50 Hz; (e) Triangle wave modulation at 100 Hz; (f) Triangle wave modulation at 500 Hz.

Mentions: In the following experiments, we adopted a sine wave and triangle wave as modulation waveforms, respectively. The generated wave amplitude is 3 V, providing a wavelength tuning range of about 0.3 nm for our DFB-LD. As the frequency is increased from 50 Hz to 500 Hz, the transmitted intensity asymmetry becomes greater, as Figure 3 shows.


A Time Difference Method for Measurement of Phase Shift between Distributed Feedback Laser Diode (DFB-LD) Output Wavelength and Intensity.

Liu Y, Chang J, Lian J, Liu Z, Wang Q, Zhu C - Sensors (Basel) (2015)

Transmitted intensity-time curves of sine and triangle modulation cases respectively at 50 Hz, 100 Hz and 500 Hz, specifically, (a) Sine wave modulation at 50 Hz; (b) Sine wave modulation at 100 Hz; (c) Sine wave modulation at 500 Hz; (d) Triangle wave modulation at 50 Hz; (e) Triangle wave modulation at 100 Hz; (f) Triangle wave modulation at 500 Hz.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541872&req=5

sensors-15-16153-f003: Transmitted intensity-time curves of sine and triangle modulation cases respectively at 50 Hz, 100 Hz and 500 Hz, specifically, (a) Sine wave modulation at 50 Hz; (b) Sine wave modulation at 100 Hz; (c) Sine wave modulation at 500 Hz; (d) Triangle wave modulation at 50 Hz; (e) Triangle wave modulation at 100 Hz; (f) Triangle wave modulation at 500 Hz.
Mentions: In the following experiments, we adopted a sine wave and triangle wave as modulation waveforms, respectively. The generated wave amplitude is 3 V, providing a wavelength tuning range of about 0.3 nm for our DFB-LD. As the frequency is increased from 50 Hz to 500 Hz, the transmitted intensity asymmetry becomes greater, as Figure 3 shows.

Bottom Line: This approach takes advantage of asymmetric absorption positions at the same wavelength during wavelength increase and decrease tuning processes in the intensity-time curve by current modulation.The phase shifts at modulation frequencies ranging from 50 Hz to 50 kHz were measured with a resolution of 0.001π.As the modulation frequency increased the shift value increased with a slowed growth rate.

View Article: PubMed Central - PubMed

Affiliation: School of Information Science and Engineering, Shandong University, Jinan 250100, China. Liuyongning1990@163.com.

ABSTRACT
A time difference method to conveniently measure the phase shift between output wavelength and intensity of distributed feedback laser diodes (DFB-LDs) was proposed. This approach takes advantage of asymmetric absorption positions at the same wavelength during wavelength increase and decrease tuning processes in the intensity-time curve by current modulation. For its practical implementation, a measurement example of phase shift was demonstrated by measuring a time difference between the first time and the second time attendances of the same gas absorption line in the intensity-time curve during one sine or triangle modulation circle. The phase shifts at modulation frequencies ranging from 50 Hz to 50 kHz were measured with a resolution of 0.001π. As the modulation frequency increased the shift value increased with a slowed growth rate.

No MeSH data available.


Related in: MedlinePlus