HIGH SPEED SEMICONDUCTOR LASERS

The strategy and methods to design high speed semiconductor lasers are reviewed here. The formalism for the analysis of intensity modulation, frequency modulation and intensity noise in quantum well lasers is first derived. Using this formalism the process of optimizing the laser structure for high speed operation is presented. In addition to the conventional factors such as the differential gain, photon density, photon lifetime and device parasitics, we also review the critical effects of carrier transport and microwave signal transmission on the dynamic characteristics and design of high speed semiconductor lasers.

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Carrier Transport in High-Mobility III–V Quantum-Well Transistors and Performance Impact for High-Speed Low-Power Logic Applications

IEEE Electron Device Letters ◽

10.1109/led.2008.2002945 ◽

2008 ◽

Vol 29 (10) ◽

pp. 1094-1097 ◽

Cited By ~ 58

Author(s):

G. Dewey ◽

M.K. Hudait ◽

Kangho Lee ◽

R. Pillarisetty ◽

W. Rachmady ◽

...

Keyword(s):

Quantum Well ◽

Low Power ◽

High Speed ◽

Carrier Transport ◽

High Mobility ◽

Performance Impact ◽

And Performance ◽

Low Power Logic

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Stability analysis of quantum-well semiconductor lasers with carrier transport effects

IEEE Photonics Technology Letters ◽

10.1109/68.789699 ◽

1999 ◽

Vol 11 (10) ◽

pp. 1226-1228 ◽

Cited By ~ 3

Author(s):

M. Kucharczyk ◽

M.S. Wartak ◽

P. Weetman

Keyword(s):

Stability Analysis ◽

Quantum Well ◽

Semiconductor Lasers ◽

Carrier Transport ◽

Transport Effects

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A Displacement Measuring Interferometer Based on a Frequency-Locked Laser Diode with High Modulation Frequency

Applied Sciences ◽

10.3390/app10082693 ◽

2020 ◽

Vol 10 (8) ◽

pp. 2693

Author(s):

Thanh Tung Vu ◽

Hong Hai Hoang ◽

Toan Thang Vu ◽

Ngoc Tam Bui

Keyword(s):

Frequency Modulation ◽

High Speed ◽

Modulation Frequency ◽

Laser Source ◽

Interference Signal ◽

Modulation Amplitude ◽

Hyperfine Component ◽

Synchronous Detection ◽

High Modulation ◽

Uncertainty Of Measurements

Laser interferometers can achieve a nanometer-order uncertainty of measurements when their frequencies are locked to the reference frequencies of the atom or molecule transitions. There are three types of displacement-measuring interferometers: homodyne, heterodyne, and frequency modulation (FM) interferometers. Among these types of interferometer, the FM interferometer has many advantageous features. The interference signal is a series of time-dependent harmonics of modulation frequency, so the phase shift can be detected accurately using the synchronous detection method. Moreover, the FM interferometer is the most suitable for combination with a frequency-locked laser because both require frequency modulation. In previous research, low modulation frequencies at some tens of kHz have been used to lock the frequency of laser diodes (LDs). The low modulation frequency for the laser source means that the maximum measurement speed of the FM interferometers is limited. This paper proposes a novel contribution regarding the application of a high-frequency modulation for an LD to improve both the frequency stability of the laser source and the measurement speed of the FM interferometer. The frequency of the LD was locked to an I2 hyperfine component at 1 MHz modulation frequency. A high bandwidth lock-in amplifier was utilized to detect the saturated absorption signals of the I2 hyperfine structure and induce the signal to lock the frequency of the LD. The locked LD was then used for an FM displacement measuring interferometer. Moreover, a suitable modulation amplitude that affected the signal-to-noise ratio of both the I2 absorption signal and the harmonic intensity of the interference signal was determined. In order to verify the measurement resolution of the proposed interferometer, the displacement induced by a piezo electric actuator was concurrently measured by the interferometer and a capacitive sensor. The difference of the displacement results was less than 20 nm. To evaluate the measurement speed, the interferometer was used to measure the axial error of a high-speed spindle at 500 rpm. The main conclusion of this study is that a stable displacement interferometer with high accuracy and a high measurement speed can be achieved using an LD frequency locked to an I2 hyperfine transition at a high modulation frequency.

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