Influence of absorption induced thermal initiation pathway on irradiance threshold for laser induced breakdown.

Biomed Opt Express

Department of Personal Care and Wellness, Philips Research, 5656AE, Eindhoven, The Netherlands.

Published: April 2015

We investigated the influence of thermal initiation pathway on the irradiance threshold for laser induced breakdown in transparent, absorbing and scattering phantoms. We observed a transition from laser-induced optical breakdown to laser-induced thermal breakdown as the absorption coefficient of the medium is increased. We found that the irradiance threshold after correction for the path length dependent absorption and scattering losses in the medium is lower due to the thermal pathway for the generation of seed electrons compared to the laser-induced optical breakdown. Furthermore, irradiance threshold gradually decreases with the increase in the absorption properties of the medium. Creating breakdown with lower irradiance threshold that is specific at the target chromophore can provide intrinsic target selectivity and improve safety and efficacy of skin treatment methods that use laser induced breakdown.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4399662PMC
http://dx.doi.org/10.1364/BOE.6.001234DOI Listing

Publication Analysis

Top Keywords

irradiance threshold
20
laser induced
12
induced breakdown
12
thermal initiation
8
initiation pathway
8
pathway irradiance
8
threshold laser
8
laser-induced optical
8
optical breakdown
8
breakdown
7

Similar Publications

Aim: Breast cancer is the second most common cancer among women and the leading cause of cancer-related mortality in this population. Numerous factors have been identified as either risk factors or protective factors for breast cancer. However, the role of Vitamin D (Vit.

View Article and Find Full Text PDF

Applying aperture-based intensity map in automated plan review of volumetric modulated arc therapy for lung cancer patients.

Quant Imaging Med Surg

January 2025

Department of Radiation Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.

Background: Volumetric modulated arc therapy (VMAT) is a popular radiotherapy technique in the clinic. As consisting of hundreds of control points in a VMAT plan it is more complex and time consuming than those conventional treatment modalities, such as intensity modulated radiation therapy. To improve the efficiency and accuracy of its quality assurance procedure, a novel automated anomaly detection method was proposed.

View Article and Find Full Text PDF

Orange carotenoid protein (OCP) is a photoactive protein that mediates photoprotection in cyanobacteria. OCP binds different ketocarotenoid chromophores such as echinenone (ECN), 3'- hydroxyechinenone (hECN), and canthaxanthin (CAN). In the dark, OCP is in an inactive orange form known as OCP; upon illumination, a red active state is formed, referred to as OCP, that can interact with the phycobilisome.

View Article and Find Full Text PDF

Purpose: With the increasing use of proton therapy, there is a growing emphasis on including radiation quality, often quantified by linear energy transfer, as a treatment plan optimization factor. The Timepix detectors offer energy-sensitive particle tracking useful for the characterization of proton linear energy transfer. To improve the detector's performance in mixed radiation fields produced in proton therapy, we customized the detector settings and performed the per-pixel energy calibration.

View Article and Find Full Text PDF

Tumour 'bulk' has historically been considered an important prognostic marker and clinical tool to guide treatment in patients with lymphoma. However, its use and definitions in trial designs varies significantly and it is unclear how this has influenced the relevance of bulk in contemporary practice. This comprehensive literature review evaluated the definitions, applications and prognostic impact of bulk in phase 3 randomised trials in four major lymphoma subtypes.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!