Refracting systems for Gaussian-to-uniform beam transformations

Jahan, Syeda R.; Karim, Mohammad A.

doi:10.1016/0030-3992(89)90008-x

Cited by 30 publications

(20 citation statements)

References 6 publications

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“…(3a) and (3b) can be used to expedite computer calculations. This definition of the transfer function permits us to relate the input angular spectrum, Ein (8), to the output spectrum, Eout (8), as…”

Section: Korpel-poon Multiple-plane-wave Scattering Theory and Transfmentioning

confidence: 99%

“…In this section we investigate the behavior of H1 (8), and on the basis of these results we explain the beam-distortion phenomena.' 5 "626 2 Equation (1) provides the starting point for our general theory.…”

Section: Transfer Functions and Beam Distortionmentioning

confidence: 99%

“…If this spread is large enough to cover some of the zeros in H 1 (8), distortion in the spatial domain of the Bragg- = (2r)/ 2 exp(-r 2 /2(o 2 ), (9) where r is the radial coordinate shown in Fig. 2 x exp 2x 2A r d 2A (11) where (-r', 8/2A) may be identified as the Fouriertransform variables.…”

Section: Transfer Functions and Beam Distortionmentioning

confidence: 99%

“…Taking the Fourier transform of both sides leads to the required transfer function, Hreq(S). This equation along with H 1 (8) represents the design equations…”

Section: Flattop Profile Shaping In the Near Fieldmentioning

confidence: 99%

“…In design problems one would like to find H 1 (8) such that it matches Hrq(b) as best as possible. By inspecting the general behavior of H 1 (8) and (6) to achieve a flattop distribution. The 1/e point of the input Gaussian spectrum and the first zeros of Hreq(b) and H 1 (a), respectively, are…”

Section: Flattop Profile Shaping In the Near Fieldmentioning

confidence: 99%

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Gaussian-beam profile shaping by acousto-optic Bragg diffraction

McNeill

Poon

1994

Appl. Opt.

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Section: Korpel-poon Multiple-plane-wave Scattering Theory and Transfmentioning

confidence: 99%

Section: Transfer Functions and Beam Distortionmentioning

confidence: 99%

Section: Transfer Functions and Beam Distortionmentioning

confidence: 99%

“…Taking the Fourier transform of both sides leads to the required transfer function, Hreq(S). This equation along with H 1 (8) represents the design equations…”

Section: Flattop Profile Shaping In the Near Fieldmentioning

confidence: 99%

Section: Flattop Profile Shaping In the Near Fieldmentioning

confidence: 99%

See 3 more Smart Citations

Gaussian-beam profile shaping by acousto-optic Bragg diffraction

McNeill

Poon

1994

Appl. Opt.

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Enhancement of gold nanorods‐assisted photothermal treatment on cancer with laser power in stepwise modulation

Kim

Kang

2022

Lasers Surg Med

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Objectives: Photothermal therapy (PTT) is a minimally invasive or noninvasive method by destructing cancer cells through selective thermal decomposition. However, a long period of laser irradiation to achieve coagulative necrosis often causes unfavorable thermal damage to the surrounding healthy tissue. The current study aims to evaluate the feasibility of temporal power modulation to improve the treatment efficacy of gold nanorods-assisted PTT against tumor tissue. Materials and Methods: A total of 25 µg/ml of PEGylated gold nanorods (PEG-GNR) was used as an absorbing agent during 1064 nm laser irradiation for PTT. Temperature monitoring was conducted on the aqueous solution of PEG-GNR for dosimetry comparison. For in vivo tests, CT-26 tumor-bearing murine models with PEG-GNR injected were treated with three irradiation conditions: 3 W/cm 2 for 90 s, 1.5 W/cm 2 for 180 s, and 3 W/cm 2 for 60 s followed by 1.5 W/cm 2 for 60 s (modulated). Ten days after the treatments, histology analysis was performed to assess the extent of coagulation necrosis in the treated tissues. Results: The temporal power modulation maintained the tissue temperature of around 50°C for a longer period during the irradiation. Histology analysis confirmed that the modulated group entailed a larger coagulative necrosis area with less thermal damage to the peripheral tissue, compared to the other irradiation conditions. Conclusion: Therefore, the power-modulated PTT could improve treatment efficacy with reduced injury by maintaining the constant tissue temperature. Further studies will examine the feasibility of the proposed technique in large animal models in terms of acute and chronic tissue responses and treatment margin for clinical translations.

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