Ultrafast Fiber Lasers and Amplifiers - Novel Light Sources for High Precision Micro Machining

2005 ◽  
Author(s):  
A. Tünnermann ◽  
A. Liem ◽  
M. Reich ◽  
F. Röser ◽  
T. Schreiber ◽  
...  
Keyword(s):  
High Precision ◽  
Fiber Lasers ◽  
Light Sources ◽  
Micro Machining

Ultrafast Fiber Lasers and Amplifiers -- Novel Light Sources for High Precision Micro Machining

2005 ◽  
Author(s):  
A. Tünnermann ◽  
A. Liem ◽  
M. Reich ◽  
S. Höfer ◽  
F. Röser ◽  
...  
Keyword(s):  
High Precision ◽  
Fiber Lasers ◽  
Light Sources ◽  
Micro Machining

LED MODULE WITH ELECTRONIC ILLUMINATION CONTROL

2019 ◽  
Vol 1 (12) ◽  
pp. 146-154
Author(s):  
V. Lisovenko ◽  
D. Lisovenko ◽  
O. Bazyk
Keyword(s):  
High Precision ◽  
Single Point ◽  
Dynamic Control ◽  
Directional Pattern ◽  
Current Strength ◽  
Design Parameters ◽  
Light Sources ◽  
Computer Design ◽  
Light Power ◽  
Electron Dynamic

Many energy saving tasks can be solved thanks to the current advances in LED technology in the production of semiconductor light sources. Modern production of solid-state LEDs guarantees high-precision compliance with the calculated design parameters of illumination devices. This opens up wide opportunities for high-precision control of the lighting parameters of a multicomponent module: light power, a directional pattern and a distribution of illumination. Today, the methodical issues of the preliminary modeling of LED illumination devices with the given parameters are fundamentally solved. There is a shift from manual calculations to computer design and need to develop and select the most effective mathematical modeling methods. The paper presents a consistent approach to the modeling of the distribution of illumination on a horizontal plane from the planar LED module, based on the Lambert type of radiation of a single point source. Simple mathematical expressions, programmed on a personal computer, are obtained. The example of a 25-LED floodlight has shown the ability of dynamic control the lighting characteristics of the module. Connecting patterns of separate LEDs or their groups allow to change the direction pattern of the lamp by the appropriate way of switching diodes with different aperture of radiation. The lighting power can be controlled within the linearity of the ampere-brightness characteristics by changing the current strength through the LED. The static selection of characteristics is controlled by the geometry of the location of discrete sources. The formation of uniform illumination of the plane is graphically illustrated. The electron-dynamic way of controlling the lighting parameters of the LED floodlight is confirmed by the inventor’s certificate.

Injection moulding of high precision optics for light-emitting diodes made of liquid silicone rubber

2016 ◽  
Vol 49 (1) ◽  
pp. 62-76 ◽  
Author(s):  
Christian Hopmann ◽  
Malte Röbig
Keyword(s):  
Energy Efficiency ◽  
Uv Radiation ◽  
High Precision ◽  
Silicone Rubber ◽  
Injection Moulding ◽  
Light Sources ◽  
Light Emitting ◽  
Semiconductor Chip ◽  
Liquid Silicone Rubber ◽  
Liquid Silicone

In the market of lighting technologies, light-emitting diodes (LEDs) gradually substitute conventional light sources. Because of their high energy efficiency and long lifetime, they are increasingly used in consumer products, interior and exterior lighting applications in the home and mobility sector as well as in industrial applications. The material properties in the surrounding area of the light-emitting semiconductor chip are crucial to the performance of LED. Although the energy efficiency of LED is higher compared to conventional light sources, temperatures exceed about 150°C close to the semiconductor chip. Especially in combination with high amounts of blue ultraviolet (UV) radiation, the materials for encapsulation cannot meet the requirements and reduce the lifetime of an LED significantly. Contrary to conventional materials, high transparent liquid silicone rubber (LSR) can resist high temperatures as well as UV radiation and offer a great freedom in design. This enables the combination of the encapsulation (primary optics) and the secondary optics in one component. The objective of an ongoing joint research project with various partners from the industry is the development of an innovative injection moulding process for high precision optics in LED applications made of LSR, which is analysed at the Institute of Plastics Processing (IKV), Aachen, Germany. Therefore, the LED board is placed in the injection mould and overmoulded with LSR. The goal is a highly integrated process with major emphasis on the reduction of components, mounting steps and costs. Furthermore, the combination of primary and secondary optics promises an improved effectiveness because losses in light power due to the transition of the primary and secondary optics are reduced.

Prediction of Cutting-Direction Burr Height in Micro-Milling

2014 ◽  
Vol 684 ◽  
pp. 131-136
Author(s):  
Cheng Yang ◽  
J. Huang ◽  
W. Yue ◽  
G.F. Shi ◽  
Gui Cheng Wang
Keyword(s):  
Experimental Data ◽  
High Precision ◽  
Micro Milling ◽  
Micro Machining ◽  
Feature Size ◽  
Burr Height ◽  
Milling Characteristics ◽  
Cutting Direction

Due to the high precision and strong molding capacity, micro-milling plays an important role in the field of micro-machining. The components machined in micro-machining is smaller than conventional components, and sometimes the generated burrs are as large as the feature size of components, so the study of micro burr control is very important. In the reseach, cutting-direction burrs are based on the traditional milling characteristics, also combined with the characteristics of micro-milling. The experimental data verify the correctness of the model well, so it provides theoretical guidance for the burrs control in micro-milling.

High Precision Machine Based on a Differential Mechanism

2014 ◽  
Author(s):  
Alberto Borboni ◽  
Elisabetta Ceretti ◽  
Alessandro Copeta ◽  
Davide Moscatelli ◽  
Rodolfo Faglia ◽  
...  
Keyword(s):  
High Precision ◽  
Degrees Of Freedom ◽  
Static Friction ◽  
Micro Machining ◽  
Concept Design ◽  
Machining Processes ◽  
Precision Machine ◽  
Macro Scale ◽  
Differential Mechanism ◽  
Servo Drives

Micromachining processes deal with the production of parts characterized by features in the micro range (i.e., with dimension lower than 1 mm). Several works are present in literature analyzing the tool behaviors, the material influence on the process, and the machine design. In fact, the downsize of the process up to the microscale needs a full review of all the knowledge coming from the meso and macro scale. As a consequence, machines suitable for micromachining processes were recently introduced in the market. Usually, these machines are classified by the classical gantry layout structure supported by a granite frame and, in order to guarantee the needed requirements of precision and accuracy in the micro scale, they are based on fluid-supported axes and active and/or passive vibration control systems. This paper proposes a new concept design: a high precision machine (HPM) based on an innovative layout exploiting a differential mechanism with three motors for two degrees of freedom using pulleys and metal belts. This new layout exhibits relevant advantages. The most significant is that all the worktable servo drives, that moves along x and y axes, are ground-fixed. This allows to isolate the working area of the machine from the servo drives. The system of pulleys and belts holding the working table slides on air bearings in order to minimize the micro vibrations induced by all the drives. A further peculiarity of the machine consists of the double z-axis each of them is motorized by a micrometer slide with linear absolute encoder. The first z-axis is equipped with a spindle for performing micro machining processes (drilling and milling). The second z-axis is equipped with a laser head for micro ablation. The servo drives of the two z-axes are controlled by the same control system of the worktable. Another important feature of the proposed layout is that the differential configuration of the xy mechanism admits the use of a constant speed signal to each control reference with no output displacements. This allows to guarantee non-inversion of motion of the servo-drives and so the avoidance of problems due to backlash and/or static friction. Drives are controlled by position and speed control loops with PID architecture, anti-windup and feed forward strategies. Controllers have been tuned by the use of a genetic algorithm applied to a dynamic model of the system. As a general consideration, the quality of the investigated micro machining processes can be improved with the designed machine structure.

scholarly journals 2.0 μm Ultra Broadband Emission from Tm3+/Ho3+ Co-Doped Gallium Tellurite Glasses for Broadband Light Sources and Tunable Fiber Lasers

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 190
Author(s):  
Jian Yuan ◽  
Weichao Wang ◽  
Yichen Ye ◽  
Tingting Deng ◽  
Yizhao Huang ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Fiber Lasers ◽  
Emission Cross Section ◽  
Emission Spectra ◽  
Gain Coefficient ◽  
Light Sources ◽  
Tellurite Glasses ◽  
Broadband Emission ◽  
Forward Energy ◽  
Co Doped

A flat 2.0 μm ultra broadband emission with a full width at half maximum (FWHM) of 329 nm is achieved in 1 mol.% Tm2O3 and 0.05 mol.% Ho2O3 co-doped gallium tellurite glasses upon the excitation of an 808 nm laser diode. The influence of Tm3+ and Ho3+ contents on 2.0 μm spectroscopic properties of gallium tellurite glasses is minutely investigated by absorption spectra, emission spectra, and lifetime measurement. In addition, emission cross section and gain coefficient of Ho3+ ions at 2.0 μm are calculated, and the maximum values reach 8.2 × 10−21 cm2 and 1.54 cm−1, respectively. Moreover, forward and backward energy transfer probability between Tm3+ and Ho3+ ions are qualitatively evaluated by the extended spectral overlap method. Large ratio of the forward energy transfer from Tm3+ to Ho3+ to the backward one (19.7) and high forward energy transfer coefficient (6.22 × 1039 cm6/s) are responsible for effective 2.0 μm emission from Ho3+ ions. These results manifest that Tm3+/Ho3+ co-doped gallium tellurite glass is suitable for potential applications of broadband light sources and tunable fiber lasers operating in eye-safe 2.0 µm spectral region.

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