Browsing by Author "Chi, Jim Y."

Now showing 1 - 18 of 18

A simple model for cavity enhanced slow lights in vertical cavity surface emission lasers
(2008-04-01)
Chou, Chia-Sheng
;
Lee, Ray-Kuang
;
Peng, Peng-Chun
;
Kuo, Hao-Chung
;
Lin, Gray
We develop a simple model for the slow lights in vertical cavity surface emission lasers (VCSELs), with the combination of cavity and population pulsation effects. The dependences of probe signal power, injection bias current and wavelength detuning for the group delays are demonstrated numerically and experimentally. Up to 65 ps group delays and up to 10 GHz modulation frequency can be achieved at room temperature at a wavelength of 1.3 mu m. The most significant feature of our VCSEL device is that the thickness of the active region is only several micrometers long. Based on the experimental parameters of quantum dot VCSEL structures, we show that the resonance effect of the laser cavity plays a significant role in enhancing the group delays.
Beam profile characteristics of InGaAs sub-monolayer quantum-dot photonic-crystal VCSELs
(2007-06-01)
Yang, Hung-Pin D.
;
Hsu, I-Chen
;
Lai, Fang-I
;
Lin, Gray
;
Hsiao, Ru-Shang
An InGaAs sub-monolayer (SML) quantum dot photonic crystal vertical-cavity surface-emitting laser (QD PhC-VCSEL) for fiberoptic applications is first time demonstrated. The active region of the device contains 3 InGaAs SML QD layers. Each of the InGaAs SML QD layer is formed by alternate deposition of InAs (< 1 ML) and GaAs. Single fundamental mode CW output power of 3.8 mW at 28 mA has been achieved in the 990 nm range, with a threshold current of 0.9 mA. Side-mode suppression ratio (SMSR) larger than 35 dB has been demonstrated over entire current operation range. The beam profile study of the PhC-VCSEL indicates that the laser beam is well confined by the photonic crystal structure of the device. The divergence angle of the devices remains almost unchanged with increasing current. (C) 2007 Elsevier B.V. All rights reserved.
Characteristics of cross-shaped polarization-switching vertical-cavity surface-emitting lasers for dual-channel communications
(2007-04-01)
Yang, Hung-Pin D.
;
Hsu, I-Chen
;
Lai, Fang-I
;
Lin, Gray
;
Kuo, Hao-Chung
The polarization switching of a cross-shaped vertical-cavity surface-emitting laser (VCSEL) for dual-channel communications is demonstrated. The polarization of the lasing output is controlled by the asymmetry in geometry of the device and direction of current injection. High output power ratio of over 5, between two orthogonal (perpendicular) polarization directions has been achieved. The lasing output of the device can be switched between two nearly orthogonal directions.
Characteristics of InGaAs submonolayer quantum-dot and InAs quantum-dot photonic-crystal vertical-cavity surface-emitting lasers
(2008-05-01)
Yang, Hung-Pin D.
;
Hsu, I. -Chen
;
Chang, Ya-Hsien
;
Lai, Fang-I
;
Yu, Hsin-Chieh
We have made InGaAs submonolayer (SML) quantum-dot (QD) and InAs QD photonic-crystal vertical-cavity surface-emitting lasers (PhC-VCSELs) for fiber-optic communications in the 990 and 1300 nm ranges, respectively. The active region of the InGaAs SML QD PhC-VCSEL contains three InGaAs SML QD layers, with each of the SML QD layer formed by alternating depositions of InAs (< 1 ML) and GaAs. The active region of the InAs QD PhC-VCSEL contains 17 undoped InAs-InGaAs QD layers. Both types of QD PhC-VCSELs exhibit single-mode characteristics throughout the current range, with side-mode suppression ratio (SMSR) larger than 35 dB. A maximum output power of 5.7 mW has been achieved for the InGaAs SML QD PhC-VCSEL. The near-field image study of the QD PhC-VCSELs indicates that the laser beam is well confined by the photonic-crystal structure of the device.
Characteristics of multileaf holey light-emitting diodes for fiber-optic communications
(2008-02-01)
Yang, Hung-Pin D.
;
Yeh, Zao-En
;
Lai, Fang-I
;
Kuo, Hao-Chung
;
Chi, Jim Y.
An oxide-confined multileaf holey light-emitting diode (LED) in the 780 nm range is reported. The device is consisted of bottom distributed Bragg reflector (DBR), quantum wells QWs), and top DBR, with a multileaf holey structure within the p-ohmic contact ring for light extraction. The spontaneous emission from under the etched holes and internally reflected lights can be extracted and collimated out of the smaller etched leaf holes. High-resolution imaging studies indicate that the device emits with smaller beams mainly through the multileaf etched holes made it suitable for fiber-optic communications.
Characteristics of P-substrate small-aperture holey light-emitting diodes for fiber-optic applications
(2007-05-01)
Yang, Hung-Pin D.
;
Liu, Jui-Nung
;
Lai, Fang-I
;
Kuo, Hao-Chung
;
Chi, Jim Y.
A small-aperture oxide-confined holey light-emitting diode (LED) on p-type GaAs substrate in the 830 nm range is reported. The device is consisted of bottom distributed Bragg reflector (DBR), quantum wells (QWs), and top DBR, with a small-aperture holey structure at the center for light extraction. The internally reflected spontaneous emission can be extracted and collimated out of the etched hole. High-resolution imaging studies indicate that the device emits with a narrower beam mainly through the central etched hole region made it suitable for fiber-optic applications.
Characteristics of single-mode InGaAs sub-monolayer quantum-dot photonic-crystal VCSELs emitting in the 990 nm range
(2008)
Yang, Hung-Pin D.
;
Hsu, I. -Chen
;
Lai, Fang-I.
;
Lin, Gray
;
Hsiao, Ru-Shang
We have made InGaAs sub-monolayer (SML) quantum dot photonic crystal vertical-cavity surface-emitting lasers (QD PhC-VCSELs) for fiber-optic applications. The active region of the device contains three InGaAs SML QD layers. Each of the InGaAs SML QD layer is formed by alternate deposition of InAs (< 1 ML) and GaAs. Single fundamental mode CW output power of 3.8 mW at 28 mA has been achieved in the 990 nm range, with a threshold current of 0.9 mA. Side-mode suppression ratio (SMSR) larger than 35 dB has been demonstrated over the entire current operation range. Near-field images of the PhC-VCSELs were also measured and studied.
Characteristics of single-mode InGaAs submonolayer quantum-dot photonic-crystal vertical-cavity surface-emitting lasers
(2006-12-01)
Yang, Hung-Pin D.
;
Hsu, I-Chen
;
Lai, Fang-I
;
Lin, Gray
;
Hsiao, Ru-Shang
An InGaAs submonolayer (SML) quantum-dot photonic-crystal vertical-cavity surface-emitting laser (QD PhC-VCSEL) for fiber-optic applications is demonstrated for the first time. The active region of the device contains three InGaAs SML QD layers. Each of the InGaAs SML QD layers is formed by alternate depositions of InAs (< 1 ML) and GaAs. A single-fundamental-mode CW output power of 3.8 mW at 28 mA has been achieved in the 990 nm range, with a threshold current of 0.9 mA. A side-mode suppression ratio (SMSR) larger than 35 dB has been demonstrated over the entire current operation range. The beam profile and near-field image study of the PhC-VCSEL indicates that the laser beam,is well confined by the photonic crystal structure of the device.
Dynamic Characteristics and Linewidth Enhancement Factor of Quantum-Dot Vertical-Cavity Surface-Emitting Lasers
(2009-05-01)
Peng, Peng-Chun
;
Lin, Gray
;
Kuo, Hao-Chung
;
Yeh, Chao-En
;
Liu, Jui-Nung
This study explores the relative intensity noise characteristics of quantum-dot vertical-cavity surface-emitting lasers (QD VCSELs). The resonance frequency and eye diagram are presented. The linewidth enhancement factor (alpha factor) of QD VCSEL is also investigated experimentally. The values of alpha factor were measured to be between 0.48 and 0.60. Moreover, a photonic RF phase shifter is examined using the QD VCSEL. A phase shifter with a total phase shift of 2 pi was demonstrated. These investigations and demonstrations will be useful in the field of QD VCSEL.
High-power single-mode submonolayer quantum-dot photonic crystal vertical-cavity surface-emitting lasers
(2007-09-01)
Lai, Fang-I.
;
Yang, H. P. D.
;
Lin, G.
;
Hsu, I. -Chen
;
Liu, Jui-Nung
A high-power, wide operation-range single-fundamental-mode InGaAs submonolayer (SML) quantum dot (QD) photonic crystal vertical-cavity surface-emitting laser (VCSEL) for fiber-optic applications was demonstrated. Single-fundamental-mode with a threshold current (I-th) of 0.9 mA and maximum continue-wave (CW) output power of 3.8 mW at 28 mA has been achieved in the 990 nm range. A side-mode suppression ratio (SMSR) larger than 35 dB has been observed over the entire current operating range. The far field measurement shows that the beam divergence angle remains very small and almost unchanged between 6.7-6.9 degrees, with the operation range increasing from 3 to 20 mA.
High-power single-mode vertical-cavity surface-emitting lasers with multi-leaf holey structure
(2006-09-01)
Yang, Hung-Pin D.
;
Hsu, I-Chen
;
Lai, Fang-I
;
Kuo, Hao-Chung
;
Chi, Jim Y.
A single-mode oxide-confined vertical-cavity surface-emitting laser (VCSEL) with multi-leaf holey structure for fiber-optic applications is demonstrated. Single fundamental mode continuous-wave output power of over 3 mW has been achieved in the 850 nm range, with a threshold current of approximately 0.5 mA. Side-mode suppression ratio (SMSR) larger than 22 dB has been measured.
Highly strained InGaAs/GaAs quantum well vertical-cavity surface-emitting lasers
(2007-06-01)
Yang, Hung-Pin D.
;
Chen, I-Liang
;
Lee, Chen-Hong
;
Chiou, Chih-Hong
;
Lee, Tsin-Dong
We report our results on the highly strained InGaAs/GaAs quantum well (QW) vertical-cavity surface-emitting lasers (VCSELs) in the 1140 to 1250 nm range. The epitaxial structures were grown on (100)GaAs substrates by metal-organic chemical vapor deposition (MOCVD). A maximum output power of more than 6.3 mW has been demonstrated. The spectral characteristics were also measured and analyzed.
InGaAs submonolayer quantum-dot photonic-crystal LEDs for fiber-optic communications
(2010-05-01)
Yang, Hung-Pin D.
;
Yeh, Zao-En
;
Lin, Gray
;
Kuo, Hao-Chung
;
Chi, Jim Y.
An InGaAs submonolayer (SML) quantum-dot photonic-crystal light-emitting diode (QD PhC-LED) with for fiber-optic applications is reported. The active region of the device contains three InGaAs SML QD layers. Each of the InGaAs SML QD layers is formed by alternate depositions of InAs (<1 ML) and GaAs. A maximum CW output power of 0.34 mW at 20 mA has been obtained in the 980 nm range. (C) 2010 Elsevier Ltd. All rights reserved.
P-substrate small-aperture holey light-emitting diodes for fiber-optic applications
(2007)
Yang, Hung-Pin D.
;
Liu, Jui-Nung
;
Lai, Fang-, I
;
Kuo, Hao-Chung
;
Xuan, Rong
An oxide-confined holey light-emitting diode (LED) on p-type GaAs substrate in the 830 nm range is reported. The device is consisted of bottom DBR, quantum wells, and top DBR, with a holey structure for light extraction. The internally reflected spontaneous emission can be extracted out of the etched hole.
Photonic-crystal light-emitting diodes on p-type GaAs substrates for optical communications
(2008)
Yang, Hung-Pin D.
;
Liu, Jui-Nung
;
Lai, Fang-I.
;
Kuo, Hao-Chung
;
Chi, Jim Y.
Oxide-confined photonic-crystal (PhC) light-emitting diodes (LEDs) on p-type GaAs substrate in the 830 nm range are reported. The device consists of a bottom distributed Bragg reflector (DBR), quantum wells (QWs), and a top DBR, with a photonic-crystal structure formed within the n-type ohmic contact ring for light extraction. The etching depth of the PhC holes is 17-pair out of the 22-pair top DBR being etched off. The internally reflected spontaneous light emission can be extracted out of PhC holes because of lower reflectance within those areas. High-resolution micrographic imaging studies indicate that the device emits light mainly through the photonic-crystal holes and it is suitable for optical communications.
Polarization Characteristics of Quantum-Dot Vertical-Cavity Surface-Emitting Laser With Light Injection
(2010-02-01)
Peng, Peng-Chun
;
Lan, Ruei-Long
;
Wu, Fang-Ming
;
Lin, Gray
;
Lin, Chun-Ting
This investigation explores experimentally the optical characteristics of long-wavelength quantum-dot vertical-cavity surface-emitting lasers (QD VCSELs). The InAs QD VCSEL, fabricated on a GaAs substrate, is grown by molecular beam epitaxy with fully doped distributed Bragg reflectors. The optical characteristics of QD VCSEL without and with light injection are studied in detail. The QD VCSEL has the potential to be used in all-optical signal processing systems.
Relative Intensity Noise Characteristics of Long-Wavelength Quantum Dot Vertical-Cavity Surface-Emitting Lasers
(2008-08-01)
Peng, Peng-Chun
;
Yeh, Chao-En
;
Kuo, Hao-Chung
;
Xuan, Ron
;
Lin, Chun-Ting
In the study we experimentally investigated the relative intensity noise (RIN) characteristics of a quantum-dot vertical-cavity surface-emitting laser (QD VCSEL). The single-mode QD VCSEL grown on a GaAs substrate is a fully doped structure. Additionally. the resonance frequency of the QD VCSEL with external light injection is as high as 19.2 GHz.
Single-mode 780 nm vertical-cavity surface-emitting lasers with multi-leaf holey structure
(2008)
Yang, Hung-Pin D.
;
Liu, Jui-Nung
;
Yeh, Zao-En
;
Lai, Fang-I
;
Lee, Tsin-Dong
A single-mode oxide-confined vertical-cavity surface-emitting laser (VCSEL) with multi-leaf holey structure for fiber-optic applications is demonstrated. The optical con. nement was done by a multi-leaf holey structure. The deep etched leaf holes were used to provide better mode confinement and suppression of higher order modes. Single fundamental mode continuous-wave output power of over 1.1mW has been achieved in the 780nm range, with a threshold current of approximately 0.9 mA. Side-mode suppression ratio (SMSR) larger than 24 dB has been measured.