High efficiency Ho:YLF slab laser with 125 Wcontinuous-wave output power

2021 ◽  
Author(s):  
Qingchen Wang ◽  
Qunlong Long ◽  
Yuan Gao ◽  
Jianyong Xue ◽  
Zhaopeng Xu ◽  
...  
2016 ◽  
Vol 55 (10) ◽  
pp. 2498 ◽  
Author(s):  
Pian Liu ◽  
Lin Jin ◽  
Xuan Liu ◽  
Haitao Huang ◽  
Deyuan Shen

2021 ◽  
Vol 2067 (1) ◽  
pp. 012009
Author(s):  
S M Vatnik ◽  
I A Vedin ◽  
M D Kolker ◽  
A A Pavlyuk

Abstract We report on highly-efficient room-temperature lasing in 5at.%Tm:KLu(WO4)2 mini-slabs side-pumped by a 35W diode bar. QCW (duty cycle ∼ 14%) output power of 1.47 W at 1908 nm has been demonstrated with optical and slope efficiencies being of 33 and 43% respectively. In our experiments, we used samples of active elements produced in the slabs form with Brewster’s angle cut faces and original laser cavity design.


2012 ◽  
Vol 51 (18) ◽  
pp. 4224 ◽  
Author(s):  
Antonio Lapucci ◽  
Marco Ciofini ◽  
Maurizo Vannoni ◽  
Andrea Sordini

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Lijie Li ◽  
Jian-Hua Jiang

Abstract The performance of thermoelectric energy harvesters can be improved by nanostructures that exploit inelastic transport processes. One prototype is the three-terminal hopping thermoelectric device where electron hopping between quantum-dots are driven by hot phonons. Such three-terminal hopping thermoelectric devices have potential in achieving high efficiency or power via inelastic transport and without relying on heavy-elements or toxic compounds. We show in this work how output power of the device can be optimized via tuning the number and energy configuration of the quantum-dots embedded in parallel nanowires. We find that the staircase energy configuration with constant energy-step can improve the power factor over a serial connection of a single pair of quantum-dots. Moreover, for a fixed energy-step, there is an optimal length for the nanowire. Similarly for a fixed number of quantum-dots there is an optimal energy-step for the output power. Our results are important for future developments of high-performance nanostructured thermoelectric devices.


Circuit World ◽  
2020 ◽  
Vol 46 (4) ◽  
pp. 243-248
Author(s):  
Min Liu ◽  
Panpan Xu ◽  
Jincan Zhang ◽  
Bo Liu ◽  
Liwen Zhang

Purpose Power amplifiers (PAs) play an important role in wireless communications because they dominate system performance. High-linearity broadband PAs are of great value for potential use in multi-band system implementation. The purpose of this paper is to present a cascode power amplifier architecture to achieve high power and high efficiency requirements for 4.2∼5.4 GHz applications. Design/methodology/approach A common emitter (CE) configuration with a stacked common base configuration of heterojunction bipolar transistor (HBT) is used to achieve high power. T-type matching network is used as input matching network. To increase the bandwidth, the output matching networks are implemented using the two L-networks. Findings By using the proposed method, the stacked PA demonstrates a maximum saturated output power of 26.2 dBm, a compact chip size of 1.17 × 0.59 mm2 and a maximum power-added efficiency of 46.3 per cent. The PA shows a wideband small signal gain with less than 3 dB variation over working frequency. The saturated output power of the proposed PA is higher than 25 dBm between 4.2 and 5.4 GHz. Originality/value The technology adopted for the design of the 4.2-to-5.4 GHz stacked PA is the 2-µm gallium arsenide HBT process. Based on the proposed method, a better power performance of 3 dB improvement can be achieved as compared with the conventional CE or common-source amplifier because of high output stacking impedance.


Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5581
Author(s):  
Zhiwei Zhang ◽  
Zhiqun Cheng ◽  
Guohua Liu

This paper presents a new method to design a Doherty power amplifier (DPA) with a large, high-efficiency range for 5G communication. This is through analyzing the drain-to-source capacitance (CDS) of DPAs, and adopting appropriate impedance of the peak device. A closed design process is proposed, to design the extended efficiency range DPA based on derived theories. For validation, a DPA with large efficiency range was designed and fabricated by using two equal devices. The measured results showed that the saturated output power was between 43.4 dBm and 43.7 dBm in the target band. Around 70% saturated drain efficiency is obtained with a gain of greater than 11 dB. Moreover, the obtained drain efficiency is larger than 50% at the 10 dB power back-off, when operating at 3.5 GHz. These superior performances illustrate that the implemented DPA can be applied well in 5G communication.


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