1μm light sources are attractive for Fourier domain optical coherence tomography (FD-OCT)
applications for ophthalmology. A semiconductor multi-quantum well structure has been designed and grown
(based on AlGaAs/GaA material) to reach the 1μm wavelength window. A compact packaged high power (>
30mW) and wide-bandwidth (>100nm) superluminescent light emit diode (SLD) is achieved with catastrophic
optical damage (COD) threshold higher than 100mW. The 1μm SLDs are suitable for high-resolution FDOCT
and SD-OCT applications. A high gain and high Psat 1050nm semiconductor optical amplifier (SOA) is
also achieved. The 1050nm SOA is a suitable gain medium for swept light sources for ultra high resolution
OCT and are ideal for in vivo retinal imaging of small choroid blood vessels below the highly reflective and
absorbing retinal pigment epithelium (RPE).
A swept light source is a type of light source whose wavelength can be quickly tuned . Typically, a swept light source is
composed of a high optical gain-medium such as a semiconductor optical amplifier (SOA) or optical gain module and a
wavelength selective component. Inphenix has developed swept light sources that cover from 800nm to 1550nm
wavelengths and are cost effective, highly linear and ideal for medical imaging and industrial measurement applications.
Applications of swept light sources have been widely investigated in real time optical imaging, optical fiber sensor
interrogator and optical component testing.
Super-luminescent laser diodes (SLD) in 800 to 1300 nm wavelength windows have been widely used in optical
coherence tomography (OCT) systems. The imaging resolution of OCT systems is proportional to the bandwidth of the
SLD light source. Here we present a new design to achieve broad bandwidth (>100nm at 1310nm) in one chip by using
two types of quantum wells.
The bandwidth of an SLD with a single active region is determined by the material bandwidth, confinement factor, and
the length of the active region. Neglecting spatial hole burning (SHB), the spectral density of amplified spontaneous
emission (ASE) can be the function of cavity length and spectral density of spontaneous emission and net gain. The main
factor that limits the ASE bandwidth is the net gain. The bandwidth of net gain has to be larger than 200 nm to obtain a
100 nm wide ASE spectrum if the ASE power is larger than several mW.
SLDs usually work at very high pump current (>400mA) to achieve high output power. From simulations, we found the
level of electron injection mainly determines the material gain. At the high injection level, large bandgap quantum wells
can get high gain and dominate the spectrum if the improper design is used. So in our design, we put the small bandgap
quantum wells at the N side to make the electron distribution in favor of long-wavelength material. Thus, and will be
balanced at high current injection level (>550mA). Figure 7 shows the measured spectrum of such structure. The
achieved spectral width is larger than 100nm and out put power is larger than 5 mW.
A unique design approach was proposed and applied to fabricate in a single chip ultra broad bandwidth and high power Superluminescent Emitting Diodes (SLEDs) at 820 nm, 1300 nm and 1550 nm windows. More than 2.5 mW, 20 mW, and 5mW of output power with a bandwidth of more than 50nm, 80 nm and 100 nm have been obtained for 820 nm, 1300 nm and 1550 nm wavelength windows, respectively. The devices were evaluated for optical coherence domain reflectometry (OCDR) and optical coherence tomography (OCT) applications, and coherence function data is quite good with a coherence measurement out to 10 mm with negligible artifacts.
Polarization-insensitive high power MQW superluminescent emitting diodes (SLEDs) were fabricated at 1300 nm with a very wide bandwidth of more than 60 nm and a very low spectrum modulation of 0.1 dB by combining high quality AR coating and several proprietary technologies including tilted cavity, window region and absorption region. Polarization dependence as low as 0.2 dB and more than 12 mW output power were obtained at 250 mA. The devices were evaluated for optical coherence domain reflectometer (OCDR) applications, and the coherence function data was quite good with a coherence measurement out to 10 mm with negligible artifacts. Devices with different cavity lengths were also fabricated and analyzed.
In this paper, a 1.55 micrometers InGaAsP/InP partially gain- coupled DFB laser monolithically integrated with electroabsorption modulator is fabricated for the first time. The threshold current and the extinction ratio are 40 mA and 11 dB respectively.
Semiconductor lasers have been the necessities of information infrastructure such as optical fiber communication and information storage. During the recent ten years, great progress has been made in China in the construction of her information infrastructure. As a basic component, semiconductor laser has also attracted much attention in academic research as well as development for industry. In China, there are several bases working on semiconductor lasers, such as State Key Laboratory on integrated optoelectronics, Institute of Semiconductors of Chinese Academy of Sciences, and Wuhan Telecommunication Devices Co., Ltd (WTD). In the State Key Laboratory on Integrated Optoelectronics, 1.3 micrometer and 1.55 micrometer InGaAsP/InP gain-coupled DFB, photonic integrated circuit (PIC), vertical cavity surface emitting lasers are being studied. Commercial class 670 nm visible lasers, 808 nm high power lasers for pumping sources, 1.3 micrometer and 1.55 micrometer InGaAsP/InP strained multiple quantum well (MQW) Fabry-Perot (FP) lasers for communications and 1.3 micrometer and 1.55 micrometer InGaAsP/InP DFB lasers have been developed in Institute of Semiconductors and WTD, respectively. Here, research and development activities on commercial class 670 nm visible laser diodes, 808 nm high power pumping lasers, 1.55 micrometer InGaAsP/InP gain- coupled DFB laser with an improved injection-carrier induced grating, high performance 1.3 micrometer and 1.55 micrometer InGaAsP/InP FP and DFB lasers for communication will be concentrated.
The progress in 1.3 micrometers wavelength InGaAsP/InP lasers for optic fiber communication and subscriber loop applications is reviewed. By using LP-MOVPE/LPE epitaxy techniques, the performance of commercial optical devices is considerably improved. The bandwidth of the 1.3 micrometers uncooled MQW-LD module could be high to 1.6GHz, threshold current Ith < 15mA, maximum fiber output power Pf >= 20mW while uniformity, reproducible, high yield are achieved. Further by growing active layer with compressive strained structure the lowest threshold current Ith equals 3.8mA was achieved with high reflection coating and the temperature performance of the SL-MQW-LD has been greatly improved, the change of slop efficiency at 25 degrees C and 85 degrees C is less than 1 dB. Using the holographic technique a high power 1.31 micrometers InGaAsP/InP multiquantum well distributed feedback laser has also been developed. The fiber output power of butterfly packaged module with optic isolator Pf > 10mW, threshold current Ith < 18mA, slop efficiency Es > 22 percent and side mode suppression ratio SMSR > 40dB. The composite triple beat CTB < -66dBc and the composite second order CSO < -56dBc by test frequencies equals 55.25 to approximately 289.25MHz with 40 NCTA channels, the carrier to noise ration CNR > 50 dB and the relative intensity noise RIN < -160dB/Hz.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.