Metallization Systems for Bonding of InP Laser Diodes to CVD-Diamond Submounts

1992 ◽  
Vol 260 ◽  
Author(s):  
A. Katz ◽  
K-W. Wang ◽  
F. A. Baiocchi ◽  
W. C. Dautremont-Smith ◽  
E. Lane ◽  
...  
Keyword(s):  
Laser Diode ◽  
Laser Diodes ◽  
Cvd Diamond ◽  
Liquid Composition ◽  
Superior Performance ◽  
Electrical Performance ◽  
Eutectic Liquid ◽  
Processing Window ◽  
First Time ◽  
Heating Duration

ABSTRACTSome metallization systems consisting of barrier metals and Au-Sn (multiple alternating layers) were studied as a bonding schemes of InP-based laser diodes to the first time used, CVD-diamond submounts. The first system to be studied, which was traditionally used in various other applications was Ti(100nm)/Pt(200nm)/Au(500nm)/Au-Sn(2.5 μm). This structure provided a molten Au-Sn layer of eutectic composition (80:20 wt%) on top of the Ti/Pt metals for about 6 sec, while heated at temperatures of 300 to 350°C, and allowed for efficient bonding of the device to the submount. Longer heating durations, however, led to reaction between Pt and Sn to consume significant amounts of Sn from the solder, thus elevating its melting temperature and resolidifying the solder. With optimum bonding conditions, a high quality bond of the InP-based laser diode to the CVD-diamond submount was observed, and a superior electrical performance of the diode was measured compared to diodes that were bonded with the standard In/BeO configurations. In order to maintain the superior performance of the InP laser diode bonded assembly but improve the thermodynamic stability of the metallurgical system and thus extending the bonding processing window, various metals such as W and Cr were studied as a replacement for the Ti/Pt barrier metals in between the CVD-diamond submount and the Au-Sn solder. While applying the W layer, a thin Ti(10nm) layer was introduced in between it and the Au-Sn to improve the solder wettability. The W layer was found to remain intact after heating at 350°C for durations as long as 5 min, and thus, due to the inert nature of the Au-Sn/W interface, the Au-Sn ratio was kept uniform at the eutectic liquid composition through a long heating duration (up to 5 min). Minimum reaction was observed, as well, at the Au-Sn/Cr interface, while executing a Ti(100nm)/Cr(200nm)/Au-Sn(1.5 μm) system, and thus allowed for an excellent bonding of the InP laser diodes to the CVD-diamond submounts.

scholarly journals Milliwatt-Level Spontaneous Emission Across the 3.5–8 µm Spectral Region from Pr3+ Doped Selenide Chalcogenide Fiber Pumped with a Laser Diode

2020 ◽  
Vol 10 (2) ◽  
pp. 539 ◽  
Author(s):  
Lukasz Sojka ◽  
Zhuoqi Tang ◽  
Dinuka Jayasuriya ◽  
Meili Shen ◽  
Joel Nunes ◽  
...  
Keyword(s):  
Environmental Monitoring ◽  
Spontaneous Emission ◽  
Wavelength Range ◽  
Laser Diode ◽  
Spectral Region ◽  
Laser Diodes ◽  
Molecular Sensing ◽  
Mid Infrared ◽  
Sensing Applications ◽  
First Time

A spontaneous emission fiber source operating in the mid-infrared (MIR) wavelength range from 3.5 to 8 µm is demonstrated for the first time at output power levels of at least 1 mW. The source is a Pr3+-doped selenide chalcogenide, multimode, glass fiber pumped with commercially available laser diodes operating at 1.470 µm, 1.511 µm and 1.690 µm. This MIR spontaneous emission fiber source offers a viable alternative to broadband mid-infrared supercontinuum fiber sources, which are comparatively complex and costly. The MIR emission wavelength range is significant for molecular sensing applications across biology and chemistry, and in medicine, agriculture, defense, and environmental monitoring.

High Heat Flux Boiling Heat Transfer for Laser Diode Arrays

2016 ◽  
Author(s):  
Todd M. Bandhauer ◽  
Taylor A. Bevis
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Laser Diode ◽  
Boiling Heat Transfer ◽  
Single Phase ◽  
Laser Diodes ◽  
Heat Fluxes ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Laser Diode Arrays

The principle limit for achieving higher brightness of laser diode arrays is thermal management. State of the art laser diodes generate heat at fluxes in excess of 1 kW cm−2 on a plane parallel to the light emitting edge. As the laser diode bars are packed closer together, it becomes increasingly difficult to remove large amounts of heat in the diminishing space between neighboring diode bars. Thermal management of these diode arrays using conduction and natural convection is practically impossible, and, therefore, some form of forced convective cooling must be utilized. Cooling large arrays of laser diodes using single-phase convection heat transfer has been investigated for more than two decades by multiple investigators. Unfortunately, either large fluid temperature increases or very high flow velocities must be utilized to reject heat to a single phase fluid, and the practical threshold for single phase convective cooling of laser diodes appears to have been reached. In contrast, liquid-vapor phase change heat transport can occur with a negligible increase in temperature and, due to a high enthalpy of vaporization, at comparatively low mass flow rates. However, there have been no prior investigations at the conditions required for high brightness edge emitting laser diode arrays: >1 kW cm−2 and >10 kW cm−3. In the current investigation, flow boiling heat transfer at heat fluxes up to 1.1 kW cm−2 was studied in a microchannel heat sink with plurality of very small channels (45 × 200 microns) using R134a as the phase change fluid. The high aspect ratio channels (4.4:1) were manufactured using MEMS fabrication techniques, which yielded a large heat transfer surface area to volume ratio in the vicinity of the laser diode. To characterize the heat transfer performance, a test facility was constructed that enabled testing over a range of fluid saturation temperatures (15°C to 25°C). Due to the very small geometric features, significant heat spreading was observed, necessitating numerical methods to determine the average heat transfer coefficient from test data. This technique is crucial to accurately calculate the heat transfer coefficients for the current investigation, and it is shown that the analytical approach used by many previous investigations requires assumptions that are inadequate for the very small dimensions and heat fluxes observed in the present study. During the tests, the calculated outlet vapor quality exceeded 0.6 and the base heat flux reached a maximum of 1.1 kW cm−2. The resulting experimental heat transfer coefficients are found to be as large a 58.1 kW m−2 K−1 with an average uncertainty of ±11.1%, which includes uncertainty from all measured and calculated values, required assumptions, and geometric discretization error from meshing.

scholarly journals Experimental Investigation of a Novel Absorptive/Reflective Solar Concentrator: A Thermal Analysis

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1281 ◽  
Author(s):  
Alok Dayanand ◽  
Muhsin Aykapadathu ◽  
Nazmi Sellami ◽  
Mehdi Nazarinia
Keyword(s):  
Experimental Investigation ◽  
Cooling System ◽  
Electrical Performance ◽  
Solar Concentrator ◽  
Cell Temperature ◽  
Compound Parabolic Concentrator ◽  
Pv Cell ◽  
Overall Efficiency ◽  
First Time ◽  
Absorber Surface

This paper presents the experimental investigation of a novel cross-compound parabolic concentrator (CCPC). For the first time, a CCPC module was designed to simultaneously work as an electricity generator and collect the thermal energy present in the module which is generated due to the incident irradiation. This CCPC module consists of two regions: an absorber surface atop the rig and a reflective region below that to reflect the irradiation onto the photovoltaic (PV) cell, coupled together to form an absorptive/reflective CCPC (AR-CCPC) module. A major issue in the use of PV cells is the decrease in electrical conversion efficiency with the increase in cell temperature. This module employs an active cooling system to decrease the PV cell temperature, optimizing the electrical performance and absorbing the heat generated within the module. This system was found to have an overall efficiency of 63%, which comprises the summation of the electrical and thermal efficiency posed by the AR-CCPC module.

MOLTEN SALT SYNTHESIS OF YF3:Yb3+/Ln3+(Ln = Er3+, Tm3+) MICROSHEETS WITH MULTICOLOR UPCONVERSION LUMINESCENCE

2013 ◽  
Vol 06 (06) ◽  
pp. 1350061 ◽  
Author(s):  
MINGYE DING ◽  
CHUNHUA LU ◽  
LINHAI CAO ◽  
YARU NI ◽  
ZHONGZI XU
Keyword(s):  
Molten Salt ◽  
Laser Diode ◽  
Upconversion Luminescence ◽  
Emission Spectra ◽  
Upconversion Emission ◽  
Molten Salt Synthesis ◽  
Molten Salt Method ◽  
Orthorhombic System ◽  
Co Doping ◽  
First Time

In this paper, highly crystalline YF 3: Yb 3+/ Ln 3+( Ln = Er 3+, Tm 3+) microsheets were successfully synthesized by a surfactant-free molten salt method for the first time. The results indicated that the as-obtained samples belonged to orthorhombic system and exhibited microsheets morphology with side lengths of 30 to 80 μm and wall thickness from 1 to 1.5 μm. By changing the dopant's species ( Ln 3+), multicolor (yellow and blue) upconversion emission can be observed in YF 3: Yb 3+/ Ln 3+ microsheets under 980 nm laser diode (LD) excitation. The upconversion mechanisms in co-doping YF 3 samples were analyzed in detail based on the emission spectra. Importantly, this approach not only proposes a new alternative in synthesizing such materials, but also opens the possibility to meet the increasing commercial demand.

scholarly journals Room Temperature CW Operation of GaN-based Blue Laser Diodes by GaInN/GaN optical guiding layers

2000 ◽  
Vol 5 (S1) ◽  
pp. 1-7 ◽  
Author(s):  
Masayoshi Koike ◽  
Shiro Yamasaki ◽  
Yuta Tezen ◽  
Seiji Nagai ◽  
Sho Iwayama ◽  
...  
Keyword(s):  
Room Temperature ◽  
Continuous Wave ◽  
Laser Diodes ◽  
Threshold Current ◽  
Crystal Defects ◽  
Blue Laser ◽  
Buffer Layers ◽  
Continuous Wave Laser ◽  
Cw Operation ◽  
First Time

GaN-based short wavelength laser diodes are the most promising key device for a digital versatile disk. We have been improving the important points of the laser diodes in terms of optical guiding layers, mirror facets. The continuous wave laser irradiation at room temperature could be achieved successfully by reducing the threshold current to 60 mA (4 kA/cm2). We have tried to apply the multi low temperature buffer layers to the laser diodes for the first time to reduce the crystal defects.

The homoepitaxial challenge: GaN crystals grown at high pressure for laser diodes and laser diode arrays

2013 ◽  
pp. 18-77 ◽  
Author(s):  
Izabella Grzegory ◽  
Michal Bockowski ◽  
Piotr Perlin ◽  
Czeslaw Skierbiszewski ◽  
Tadeusz Suski ◽  
...  
Keyword(s):  
High Pressure ◽  
Laser Diode ◽  
Laser Diodes ◽  
Laser Diode Arrays

scholarly journals The coherence of powerful laser diodes and formation of lasing channels

2019 ◽  
Vol 220 ◽  
pp. 02013
Author(s):  
Alexey Rzhanov
Keyword(s):  
Laser Diode ◽  
Laser Diodes ◽  
Laser Resonator ◽  
Powerful Laser ◽  
High Power Laser ◽  
Power Laser ◽  
Planar Laser ◽  
Wide Contact ◽  
The Relationship ◽  
High Power Laser Diode

The effect of the radiation coherence length on the lasing channels lateral dimensions in a planar laser diode with a wide contact is considered. The relationship between the coherence of high-power laser diode radiation, its spectrum and the nonlinear optical properties of the laser resonator active medium is discussed.

Performance Study of a GaAs Based Laser Diode Chip in a Condensing Environment

2009 ◽  
Author(s):  
Sushma Madduri ◽  
Bahgat G. Sammakia ◽  
William Infantolino ◽  
Satish C. Chaparala ◽  
Lawrence C. Hughes ◽  
...  
Keyword(s):  
Output Power ◽  
Laser Diode ◽  
Laser Diodes ◽  
Accelerated Aging ◽  
Climatic Conditions ◽  
Laser Output ◽  
Laser Output Power ◽  
Stress Tests ◽  
Performance Study ◽  
Aerospace Material

This paper presents a performance study done on semiconductor laser diodes in a moisture condensing environment. Devices with laser diodes are used in a wide variety of electronic applications and in various climatic conditions. The motivation behind this study is a common environmental exposure, where a device using a laser diode is brought into a relatively humid environment (a building) from a cold, outside environment. Under such conditions, condensation occurs on various components of the device, including the diode, and could affect the laser output power. Reliability of the device is a critical concern since the laser diode and the lens are susceptible to failure due to such repetitive condensation conditions. The test vehicle chosen for this study was a 980nm laser diode. These are used in products for a broad range of markets, including data communications, aerospace, material processing, scientific and defense industries [1–3]. These products may be used in environmental conditions that could result in condensation within the product. A hermetic package could address this concern, but it is an expensive option. Nonhermetic packaging for the laser component could help lower the cost of these devices; however reliability is a potential concern. Prior research on laser diodes consists of various reliability measurements on 980nm lasers using stress tests (e.g. accelerated aging tests; thermal cycling tests) [3–6]. Reliability analysis of laser diodes specifically addressing condensation measurements has not been previously reported. A Military Standard Specification [MIL-STD-883E Method 1004.7] titled, ‘Moisture resistance test’ was used to conduct this reliability study [10]. An experimental setup was designed and fabricated. A photonic package with a 980nm laser diode was subjected to repetitive condensing cycles and laser output power was recorded as a function of time, temperature and humidity. The variation in laser output power due to condensation was observed and quantified. The focus of this paper is on performance degradation of the laser diode. The possible mechanisms for this degradation are currently being investigated.

Plasma-assisted highly efficient synthesis of Li(Ni1/3Co1/3Mn1/3)O2 cathode materials with superior performance for Li-ion batteries

RSC Advances ◽  
2015 ◽  
Vol 5 (92) ◽  
pp. 75145-75148 ◽  
Author(s):  
Qianqian Jiang ◽  
Lei Xu ◽  
Jia Huo ◽  
Han Zhang ◽  
Shuangyin Wang
Keyword(s):  
Solid State ◽  
Cathode Materials ◽  
Oxygen Plasma ◽  
Superior Performance ◽  
Li Ion Batteries ◽  
Efficient Synthesis ◽  
Highly Efficient ◽  
Li Ion ◽  
First Time

We, for the first time, prepared layered Li(Ni1/3Co1/3Mn1/3)O2 by a novel oxygen plasma-assisted solid-state approach, which almost shows the best performance among ternary cathode materials for Li-ion batteries.

Deep eutectic liquid organic salt as a new solvent for carrier-mediated hollow fiber liquid phase microextraction of lead from whole blood followed by electrothermal atomic absorption spectrometry

2017 ◽  
Vol 41 (15) ◽  
pp. 7038-7044 ◽  
Author(s):  
Leila Alavi ◽  
Shahram Seidi ◽  
Ali Jabbari ◽  
Tahmineh Baheri
Keyword(s):  
Liquid Phase ◽  
Hollow Fiber ◽  
Whole Blood ◽  
Electrothermal Atomic Absorption Spectrometry ◽  
Absorption Spectrometry ◽  
Organic Salt ◽  
Eutectic Liquid ◽  
Liquid Phase Microextraction ◽  
First Time

In the present work, for the first time, a new carrier-mediated hollow fiber liquid phase microextraction (CM-HFLPME) technique was applied for the determination of lead in whole blood samples by means of ETAAS.

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