Blue high power InGaN semiconductor laser diodes: Design optimization of laser bars and single emitters for best performance and reliability

König, Harald; Gerhard, Sven; Ali, Muhammad; Heine, Urs; Tautz, Soenke; Eichler, Christoph; Brüderl, G.; Peter, M.; Lell, A.; Behringer, Martin; Keidler, Markus; Haupeltshofer, Tobias; Walter, Christoph; Baumann, Markus; Balck, Anne; Krause, Volker

doi:10.1117/12.2543306

Cited by 9 publications

(4 citation statements)

References 7 publications

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“…A need for a noninvasive, portable clinical device for direct, accurate and real-time in-vivo hematocrit measurement on patients suffering from anemia or polycythemia as well as blood donors, surgical patients, and trauma victims still exists. Scalable optical contrast of hemoglobin molecule, advancement of smaller sized optical sources (laser diodes, high power LEDs) [3,4] and highly sensitive broadband ultrasound detectors [5,6] enable photoacoustic technique to emerge as a potential candidate for clinically acceptable screening tool [7]. Oxygenated or deoxygenated hemoglobin molecule inside a RBC acts as chromophore to produce pressure wave (photoacoustic signal) absorbing very short duration (of the order of nanosecond) optical energy pulses.…”

Section: Introductionmentioning

confidence: 99%

Acquiring photoacoustic signature of hematocrit variation from plexus layer of in-silico human skin phantom

Banerjee¹,

Sarkar²,

Karmakar³

2021

Biomed. Phys. Eng. Express

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Optical penetration inside human skin is constrained by the wavelength dependent scattering and absorption losses by tissue microstructure and chromophores. This computational study investigates whether the signature of hematocrit variation from plexus i.e., the first skin layer having very small blood volume percentage distributed in capillary vessels, is retained by the detected photoacoustic response. The in-silico skin phantom is irradiated by a light source equivalent to a small footprint and low power (below 5 W) continuous wave LASER diode. As the low fluence can be compensated by exploiting strong absorption by targeted chromophores (hemoglobin molecules), an irradiation of wavelength 405 nm has been used to generate detectable pressure from capillary blood vessels of plexus. Optical energy deposition inside the tissue has been modelled using Monte Carlo technique and the pressure wave is computed using k-wave. It is found that with the increase in hematocrit from 10% to 50%, photoacoustic amplitude monotonically increases and gets almost doubled. The increment is about 30% in the range of hematocrit of physiological interest (from 30% to 50%). The variation follows a quadratic relationship for the entire hematocrit range. This photoacoustic signature of hematocrit variation has further been validated against minimum detectable pressure (800 Pa). This numerical model is expected to be an important basis to realize the idea of low cost small footprint in-vivo photoacoustic hematocrit measurement device.

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Section: Introductionmentioning

confidence: 99%

Acquiring photoacoustic signature of hematocrit variation from plexus layer of in-silico human skin phantom

Banerjee¹,

Sarkar²,

Karmakar³

2021

Biomed. Phys. Eng. Express

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“…However, despite the progresses, the power from a single blue laser chip is still more than four times lower than that of "more traditional" GaAs-based high power laser chips used for emission in the 800 nm to 1000 nm range. Indeed, current commercially available GaN laser chips are able to emit up to 5 W, 4 as compared to more than 20 W of GaAs chips. Therefore, in order to obtain the hundreds of watts typically requested by high speed industrial materials processing, multiple chips must be combined in a single package to obtain to so-called "multi-emitter modules".…”

Section: Introductionmentioning

confidence: 99%

In-fiber stabilization of high-power blue multiemitter modules

Serafini,

Cavagnetto,

Zaimovic

et al. 2024

High-Power Diode Laser Technology XXII

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“…In particular, when combined, the latter two listed functionalities realize the Phase and Amplitude Setting circuits (PASs), key components in Radio Frequency (RF) front ends, and more specifically, for phased array systems. In addition to millimeter-wave and microwave circuits in high-end electronic systems, GaN has been extensively utilized in the fabrication of optoelectronic devices, such as lasers [11][12][13][14][15], light emitting diodes (LEDs) [16][17][18][19][20][21], and solar cells [22][23][24].…”

Section: Introductionmentioning

confidence: 99%

AM/AM and AM/PM Characterization of a GaN Phase and Amplitude Setting Circuit

Colangeli,

Das,

Longhi

et al. 2023

Electronics

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This contribution presents the AM/AM and AM/PM characteristics of a 6-bit Phase and Amplitude Setting Circuit realized in Gallium Nitride technology and operating at the Ku band. A test bench, based on three vector receivers and an absolute power reference, has been purposely devised to capture the deviation with respect to the linear behavior (known by the S-parameters) for both the magnitude and the phase of the vector response. The complete 64-state constellation is reported up to a 37 dBm of input power level, at which the effects of the static AM/AM and AM/PM distortion become evident, with about 3 dB of gain compression and 2.7 deg of phase conversion. The key figure of merit of the proposed test bench is the capability of operating with very high driving power levels (potentially up to 41 dBm), with possible applications in phased arrays, AESAs, and other signal conditioning systems.

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Blue high power InGaN semiconductor laser diodes: Design optimization of laser bars and single emitters for best performance and reliability

Cited by 9 publications

References 7 publications

Acquiring photoacoustic signature of hematocrit variation from plexus layer of in-silico human skin phantom

Acquiring photoacoustic signature of hematocrit variation from plexus layer of in-silico human skin phantom

In-fiber stabilization of high-power blue multiemitter modules

AM/AM and AM/PM Characterization of a GaN Phase and Amplitude Setting Circuit

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