Circular-grating Distributed Bragg Reflector Research Articles

Modulation bandwidth of planar circular grating distributed bragg reflector lasers

This paper presents an analysis of the 3-dB-modulation bandwidth in planar circular grating distributed Bragg reflector lasers. The theoretical model takes into account both the spatial hole burning effect and the transverse and longitudinal field distribution. That model allows the study of the influence of real structure parameters on the 3-dB-modulation bandwidth.

Excess noise factor in circular grating distributed Bragg reflector lasers

In this paper, the excess quantum noise in circular grating distributed Bragg reflector (CG-DBR) lasers is analyzed taking the effect of mode non-orthogonality into account. An expression for the excess noise factor is derived. Numerical results obtained for CG-DBR laser reveal that real parameters of the laser structure have a remarkable effect on the level of excess quantum noise.

Nonlinear operation of a planar circular-grating DBR laser

An approximate method for the analysis of the nonlinear operation of a planar circular-grating distributed Bragg reflector laser is presented. The analysis is based upon vector-wave self-consistent coupled-mode equations modified to take into account gain saturation effects. With the help of an energy theorem and threshold field approximation, an approximate formula relating small-signal gain to the output power and laser parameters is derived. The laser characteristics obtained reveal behavior of the optimal coupling strength of the Bragg reflector, which provides maximal power efficiency as a function of the laser parameters. It is also shown that the gain saturation effect provides mode selectivity in the laser structure.

Threshold gain and threshold current analysis of circular grating DFB and DBR lasers

A TE-cylindrical wave threshold gain and threshold current analysis is presented for circular grating distributed feedback (CG-DFB) and circular grating distributed-Bragg-reflector (CG-DBR) lasers. Mode properties of CG-DFB/DBR lasers are discussed. It is found that the threshold gain, threshold current density and threshold current of CG-DBR lasers can be much lower than those of CG-DFB lasers. >

Electrically pumped circular-grating distributed-Bragg-reflector lasers

The design, fabrication, and lasing characteristics of electrically pumped circular-grating distributed-Bragg-reflector (CG-DBR) surface-emitting lasers, were studied. Surface-emitted lasing action was achieved at room temperature under pulsed condition. Although the measured threshold current is still higher than theoretical calculations, CW operation should be possible by improving the fabrication and the device structure. >