Browsing by Author "Cheng, PH"

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0.66 mu m InGaP/InGaAlP single quantum well microdisk lasers
(1998-06-01)
Pan, JS
;
Cheng, PH
;
Lee, TD
;
Lai, YC
;
Tai, KC
Visible emitting microdisk lasers with single InGaP/InGaAlP quantum well were demonstrated for the first time. Large spontaneous emission factors beta of 0.12 and 0.08 were observed for 5 and 10 mu m diameter disks, respectively.
Far-field emission narrowing effect of microdisk lasers
(1998-05-04)
Lee, TD
;
Cheng, PH
;
Pan, JS
;
Tsai, RS
;
Lai, Y
Far-field intensity distribution of semiconductor microdisk lasers is experimentally measured and the emission angle is found to be much smaller than that of a planar source with the same near-held width. In fact the emission angle is determined mainly by the disk radius instead of the disk thickness. A scalar diffraction theory in the cylindrical coordinate is developed to explain such an emission-angle-narrowing phenomenon and numerical calculation based on a vectorial diffraction theory is carried out to explain the measured polarization state. (C) 1998 American Institute of Physics.
Mode emission characteristics of semiconductor microdisc and microring lasers
(1996-10-01)
Lee, TD
;
Cheng, PH
;
Pan, JS
;
Tai, K
;
Lai, Y
We fabricate both microdisc and microring InGaAsP-InGaAs quantum well semiconductor lasers using an etching-and-bonding technique. Their emission properties are studied by optical pumping at 77 K. Single mode lasing is achieved for discs with a diameter of 5 mu m. Multimode emission is observed for rings with larger diameters. Both fundamental and higher order lasing modes are observed and are found to exhibit interesting emission characteristics.
Mode emission properties of semiconductor micro-disk and micro-ring lasers
(1999)
Lee, TD
;
Cheng, PH
;
Pan, JS
;
Tai, K
;
Lai, Y
We have successfully fabricated optically pumped semiconductor micro-disk and micro-ring lasers under the InGaAsP/InGaAs system at the 1.5 mu m wavelength and under the InGaP/InGaAlP system at the 0.66 mu m wavelength. The spontaneous emission factor beta of these micro-lasers is estimated directly from their output-pump curves and its dependence on the cavity volume is verified. Interesting phenomena regarding the far-field emission pattern and lasing linewidth of these micro-cavity lasers are experimentally observed and theoretically studied.
Spontaneous emission factor versus cavity volume in low dimensional photonic micro-cavities
(1997-10-15)
Cheng, PH
;
Lee, TD
;
Pan, JS
;
Lai, Y
;
Tai, K
Micro-ring and micro-disk lasers an formed at the same time by transferring the epitaxial layers of 1.55 mu m wavelength InGaAs/ZnGaAsP quantum wells on a glass substrate. The spontaneous emission factor beta in such micro-rings of 5 mu m diameter and 0.2 x 0.5 mu m(2) cross-section is 0.16, which is four times that in micro-disk lasers of the same diameter. The result confirms for the first time that the micro-ring being a lower dimensional photonic system has a larger beta. Study of beta versus the cavity size indicates that the observed spontaneous emission factor is approximately the reciprocal of the normalized cavity volume, when normalization is done to the cubic of the wavelength in the medium. (C) 1997 Elsevier Science B.V.
Spontaneous emission factor versus cavity volume in low dimensional photonic micro-cavities
(1997-10-15)
Cheng, PH
;
Lee, TD
;
Pan, JS
;
Lai, Y
;
Tai, K
Micro-ring and micro-disk lasers an formed at the same time by transferring the epitaxial layers of 1.55 mu m wavelength InGaAs/ZnGaAsP quantum wells on a glass substrate. The spontaneous emission factor beta in such micro-rings of 5 mu m diameter and 0.2 x 0.5 mu m(2) cross-section is 0.16, which is four times that in micro-disk lasers of the same diameter. The result confirms for the first time that the micro-ring being a lower dimensional photonic system has a larger beta. Study of beta versus the cavity size indicates that the observed spontaneous emission factor is approximately the reciprocal of the normalized cavity volume, when normalization is done to the cubic of the wavelength in the medium. (C) 1997 Elsevier Science B.V.