A Study of Biophotonics

By G Lee et al.

Biophotonics is the study of the interaction of light with biological material, where “light” includes all forms of radiant energy whose quantum unit is the photon. A more recent development of photonics, much of biophotonics is focused on translating discoveries in the sciences around lasers, light and imaging into useful medical tools. Medical imaging and in vitro diagnostics are just two of the many applications of biophotonics that already had an enormous positive impact on our lives. Besides advancing the frontiers of medical technology, biophotonics is also being applied to non-medical applications. As the experts in the field attest, the promise of future developments in biophotonics is nothing short of extraordinary. Light and other forms of radiant energy can be used to image, analyze and manipulate living tissue at cellular and molecular level, in a noninvasive or minimally invasive manner. The region of the electromagnetic spectrum of interest comprises of wavelengths shorter than 1 mm.

Pls follow the link for complete article

Light Quantification: Radiometry & Photometry

Light is electromagnetic radiation. What we see as visible light is only a tiny fraction of the electromagnetic spectrum, extending from very-low-frequency radio waves through microwaves, infrared, visible and ultraviolet light to x-rays and ultra energetic gamma rays. Our eyes respond to visible light; detecting the rest of the spectrum requires an arsenal of scientific instruments ranging from radio receivers to scintillation counters.

Radiometry is the science of measuring light in any portion of the electromagnetic spectrum. In practice, the term is usually limited to the measurement of infrared, visible, and ultraviolet light using optical instruments.

Meanwhile Photometry is the science of measuring visible light in units that are weighted according to the sensitivity of the human eye. It is a quantitative science based on a statistical model of the human visual response to light -- that is, our perception of light -- under carefully controlled conditions.

The following link give you an easy to understand reading material that describe the fundamental concepts used to quantify the light, i.e. which are categorized as the Radiometry and Photometry

Organic light-emitting-diode lighting overview

By: Yuan-Sheng Tyan
Tyan Consulting, 613 Old Woods Road, Webster, New York 14580

                                                                Abstract

For organic light-emitting-diode (OLED) lighting to be successful, it is critical that it be properly positioned in the marketplace. It is also critical that both the performance and cost be competitive against other lighting technologies in the selected marketplace. This presentation gives an overview of OLED lighting technology from these perspectives. It shows that OLED lighting products should be positioned as luminaires and not light bulbs, which affects both the performance and price expectations. Laboratory OLED devices already demonstrated efficacies that are more than competitive against luminaires based on other lighting technologies. There is potential for substantial further improvement in efficacy. The greatest opportunities come from light-extraction efficiency improvements and from an improved blue emitting system. There has been great recent progress in the OLED device lifetime. To be acceptable as luminaires, however, OLED may need even more lifetime improvements. Not all the improvements need to come from OLED technology improvement, however. We discuss other means to effectively improve the lifetime of OLED lighting panels and show why there is optimism that, with volume production, OLED lighting can be competitive against other luminaires even on the first-cost basis.

Complete article can be read in J. Photon. Energy. 1(1), 011009 (January 20, 2011). doi:10.1117/1.3529412, available at the following link: http://bit.ly/1xCtFA4

Green Photonics: the role of photonics in sustainable product design

By:

1. Berit Wessler, Member of the Board of Stakeholders Photonics21, OSRAM GmbH, Hellabrunner Str.1, 81543 Munich
2. Ursula Tober, Economist/Consultant, VDI Technologiezentrum GmbH – Photonics21 secretariat, VDI Platz 1, 40468 Duesseldorf

                                                                 ABSTRACT

Photonic technologies will play an increasingly significant role in reducing our environmental impact. In addition to the direct eco-benefits derived from the products themselves, green photonics will also impact the product design and manufacturing processes employed. Examples are discussed covering laser manufacturing, solid-state lighting, solar cells and optical communications. The importance of considering the full lifetime environmental impact of products is discussed, including raw materials, manufacture, use, and end of life issues. Industrial and legislative strategies are reviewed, and a number of specific measures are presented for accelerating the development of green photonics technologies and promoting their adoption into society.

Complete article can be followed at: http://bit.ly/1jf1gqe

PHOTONICS FOR AGRICULTURE: Studies of tropical fruit ripening using three different spectroscopic techniques

 By: Hao Zhang ; Jing Huang ; Tianqi Li ; Xiuxiang Wu ; Sune Svanberg ; Katarina Svanberg

The ability to discriminate between mature and immature fruits is very important both for fruit customers as well as for the fruit dealers. If the fruits are immature or overmature, the structure and taste are compromised and the value is reduced. Maturity signifies a quality stage where the fruits are acceptable for purchase but not necessarily ripe and in an optimal status for consumption [1,2]. Clearly, it is important to find the ripening stage when the fruits are considered to be of the desired quality. Many kinds of fruits can be harvested when considered mature but not ripe—ripeness will follow after some storage time, and is then followed by decay processes. Generally speaking, skin color, firmness, and size are the most used maturity indices for fruits [1,3]  and are often used by customers when purchasing the fruits. However, such assessments lack a fully reliable identification of the fruit ripening stage. Therefore, other biochemical and physiological parameters should be considered to determine the optimal fruit harvesting/consumption time. Sugar concentration, acidity, and starch content are the customary indices used to determine fruit ripening [1,4]. However, they cannot provide all the information needed to accurately identify the fruit ripening stage. Moreover, invasive methods are generally used to analyze these parameters to evaluate the fruit ripening.

In recent years, visible-near-infrared (vis-NIR) spectroscopy has been shown to be a promising, nondestructive method to evaluate fruit ripening, since it provides reliable information on internal characteristics of various fruit species [5–7]. However, this approach requires a very complex processing of data to build up calibration and prediction models [8]. Based on the vis-NIR spectroscopy, a simple and easy to perform measurement method, the “index of absorbance difference (IAD)” technique that strongly correlates with the chlorophyll content and the ethylene production of fruits, was introduced for nectarine and peach fruits [9–11]. However, this method cannot provide the precise days for the fruit ripening stage. Furthermore, it cannot differentiate the ripeness stage from the maturity of the fruits. In the present article, we demonstrate a noninvasive combination optical method based on reflectance and fluorescence spectroscopies together with the gas in scattering media absorption spectroscopy (GASMAS) technique, to study the ripening period of tropical fruits. The study focuses on measuring the changes of chlorophyll content using reflectance and fluorescence spectroscopies, and the changes of oxygen content using the GASMAS technique.

Chlorophyll is an essential pigment of fruits and is involved in fruit coloration, influencing the variations of color from green to yellow or red, when additional pigments are formed. For most fruits, the color will change during the ripening process. Therefore, the chlorophyll concentration is a major indicator of the physiology in fruit maturation/ripening. Usually, chlorophyll analysis is performed with spectrometry, including reflectance and fluorescence spectroscopies [12–14]. Thus, such techniques could be attractive tools to qualitatively estimate the changes of chlorophyll content in the fruit ripening process.

Molecular oxygen is a biologically active gas, and the oxygen concentration in fruits is of crucial importance for the ripening process and the quality of the fruits. Oxygen availability influences metabolic respiration, which leads to the synthesis of organic matter and the energy generation needed for the life processes. A common way to analyze gases in situ is to use absorption spectroscopy, which employs a narrow-band light source interrogating a fixed-length gas cell in combination with the use of the Beer-Lambert law. However, in porous materials such as fruits, the light is heavily scattered, which results in an undefined absorption path length. To handle this problem, the nonintrusive and easily implemented technique GASMAS was introduced, which is based on tunable diode laser absorption spectroscopy combined with wavelength modulation spectroscopy (WMS) techniques [15]. GASMAS has already been applied to the study of gas exchange in fruits [16,17]. We have now extended the use of the GASMAS technique to study the changes of oxygen content during the fruit ripening process.

Sketch of the system:

Experimental arrangement for the measurements of reflectance spectra as well as the fluorescence spectra 

(a) and for the monitoring of the second-harmonic wavelength modulation spectroscopy (2f WMS) signal of oxygen using GASMAS (b), TIA is a transimpedance amplifier.

Complete Article can be read at:
J. Biomed. Opt. 19(6), 067001 (Jun 02, 2014). doi:10.1117/1.JBO.19.6.067001
Open Access, available at: http://bit.ly/1ifMNtN

Call for Papers: International Seminar on Photonics, Optics, and its Applications (ISPhOA 2014)

The Department of Physics FTI ITS Indonesia is proundly to host the the International Seminar on Photonics, Optics, and its Applications (ISPhOA 2014) on 14 - 15 October 2014 at Sanur Paradise Plaza Hotel, Sanur Bali.

The idea to hold the seminar is to bring together students, scientists, and engineers that involved in research and development of technologies

related to photonics, optics, and its applications, which come from different backgrounds and experiences.

This event will provide opportunity to participants to disseminate their recent original research findings, discussing current issues, and exchange of ideas related to photonics and optics technologies. It is also hoped to promote transfer of R & D outcomes into applications

that match with industrial and societal needs nationwide, as well as for the ASEAN regions.It is also hoped to promote transfer of R & D outcomes into applications that match with industrial and societal needs nationwide, as well as for the ASEAN and ASIA regions.

The ISPhOA organizer would like to cordially invite potential original and unpublished works, that are related to any (but not limited to) areas listed below:

• Theoretical Optics  and Photonics
• Computational Optics
• Light Source Technology
• Optical and Photonics Systems
• Optical Sensors
• Nonlinearity in Optics and Photonics
• Nanoscale Optics and Photonics
• Integrated Optics
• Photonics Materials & Metamaterials
• Imaging system, Image processing, and Machine Vision
• Optical Metrology & Instrumentation
• Optics and Photonics for Agriculture, Astronomy, Biology and Medicine, Renewable Energy
• Optoelectronics  and Laser applications

The contribution should be written in the format as given in the template and submitted through the SPIE Submission and Review System (SPIE SRS). The submitted contributions will be peer-reviewed, based on its originality, novelty, scientific contributions, and goodness of presentation criteria.

For detailed of information concerning the submission guidelines, please visit our official website at: http://www.isphoa2014.org/pages/paper-submission

Succesfull contributions that fulfill the selection standard will be will be notified directly to the contributors by email, and invited to present their works orally or in poster format during the seminar program. All presented paper will be published in the Proceeding of ISPhOA 2014 which will be as a volume in the Proceedings of SPIE series. These published papers will also being available in the SPIE Digital Library.

Two Distinguished best winners for both  Oral and Poster Presentations  will be awarded a prize  and certificate from the organizer of the ISPhOA 2014, and will be given  during the Closing Ceremony.

The committee will also select some highly esteemed papers, and will receive invitation  to submit extended version of their works to the Journal of Optics (JOPT) for further normal peer-reviewing process.

We are welcoming your contribution and looking forward to seeing you and your colleagues on October 14th - 15th 2014 in Sanur Bali.

To download the CFP leaflet (A4), pls.  klick here
To download the CFP poster (A3), pls.  klick here

International Year of Light 2015

Pada tanggal 20 Desember 2013, Majelis Umum PBB dalam sidang nya yang ke 68, mendeklarasikan bahwa tahun 2015 sebagai Tahun Internasional Cahaya dan Tahun Teknologi tentang Cahaya (International Year of Light and Light-based Technologies, IYL 2015)

Pencanangan tahun internasional ini adalah atas insitiatif konsorsium besar dari berbagai lembaga ilmiah internasional dengan UNESCO, dengan melibatkan stakeholder berasal dari berbagai  asosiasi masyarakat ilmiah terkait optik dan fotonik, lembaga2 pendidikan, industri teknologi terkait, NGO, serta sektor swasta lainnya.

Deklarasi Tahun Internasional Cahaya ini difokuskan pada berbagai bidang tematik dalam sains cahaya dan berbagai aplikasi terkaitnya, dimana UNESCO telah mengakui pentingnya nilai strategis dari teknologi optika dan fotonika ( light-based technologies) dalam menunjang pembangunan berkelanjutan dan memberikan solusi bagi berbagai permasalahan dan tantangan global dalam energi, pendidikan, pertanian, dan kesehatan. Cahaya telah memainkan peran yang sangat vital dalam kehidupan keseharian, dan telah menjadi ranah kajian lintas bidang keahlian dalam perkembangan sains abad ke 21 ini. Perkembangan ini telah merevolusi teknologi kedokteran, komunikasi internet, serta merupakan  penghubung utama aspek bagi budaya, ekonomi, dan politik dalam masyarakat global sekarang ni.

Ketua pengarah panitia peringatan IYL 2015 mengatakan "An International Year of Light is a tremendous opportunity to ensure that international policymakers and stakeholders are made aware of the problem-solving potential of light technology. We now have a unique opportunity to raise global awareness of this.”

selengkapnya ikuti link berikut

Untuk mengunduh presentasi terkait program IYL 2015, klik tautan berikut: http://bit.ly/1xvQu8F

Assalaamu 'alaikum w.w.

Para kolega dan sahabat ysh,
setelah sekian lama tidak aktif, alhamdulillah blog ini bisa dipulihkan kembali...
Mohon maaf atas kondisi ini..
Atas perhatian selama ini diucapkan banyak terima kasih.
Wassalaamu 'alaikum w.w

Hormat saya,
Aulia Nasution

The Physics of PDT

PDT atau dalam kepanjangannya Photodynamic Therapy adalah suatu bentuk terapi tumor / kanker dengan memanfaatkan cahaya. Prinsip perlakuan terapi ini adalah dengan memanipulasi sifat penyerapan foton cahaya oleh tissue tumor / kanker. Proses manipulasi ini dilakukan dengan jalan mengubah sensitivitas penyerapan radiasi cahaya oleh tissue tumor / kanker ini relatif terhadap jaringan sehat disekitarnya. Untuk keperluan ini digunakan suatu bahan yang dikenal sebagai photosensitizer.

Secara skematis, bagaimana treatment PDT dilakukan dijelaskan dalam gambar berikut:

Sumber: Niemz, M.H., Springer Verlag 2007

Pemberian suntikan bahan sensitizer akan terdistribusi keseluruh jaringan, baik jaringan sehat maupun tumor. Akan tetapi, karena sifat target specific dari bahan ini, maka bahan sensitizer akan tertahan dan terakumulasi pada sel tumor target yang dituju. Sementara pada tissue lainnya, akan mengalami clearance, dengan laju yang lebih besar. Akibatnya terjadi distribusi konsentrasi bahan sensitizer yang lebih besar pada target cell.

Beberapa hari setelah pemberian bahan sensitizer, beberapa literatur memberikan angka berkisar 3 hari, dilakukan penyinaran oleh laser, atau sumber cahaya lain yang sesuai.

Akibat akumulasi bahan sensitizer pada jaringan tumor target tadi, maka by designed, terjadi penyerapan radiasi laser yang sangat signifikan dibandingkan jaringan sekitar. Dengan jalan ini, maka efek interaksi cahaya dengan sensitized cell yang diharapkan akan terjadi, dan dihasilkan suatu efek nekrosis dari sel. Dengan jalan ini sel tumor / kanker yang dituju dapat dimatikan.

Beberapa sifat ideal yang perlu dipertimbangkan dalam pemilihan bahan fotosensitizer dapat ditunjukkan dalam Tabel berikut [Allison, R.A., Elsevier 2004]

selengkapnya ...<under construction>

Optics or photonics ?

Pembaca yang budiman,

berikut saya kutipkan tulisan dari Susan Curtis (optics.org), tentang diskursus terminologi optics vs photonics. Juga perdebatan yang terjadi didalamnya (selengkapnya pada tautan yang diberikan).

Selamat membaca.
Salam..

=================================================================

Optics or photonics: what’s in a name?

Sumber: http://optics.org/cws/article/research/32348

What do the terms "optics" and "photonics" mean to you? Leading researchers have had their say - and now it’s your turn.

It started off as an innocent enough question. Claire Bedrock, the publisher of Journal of  Optics A: Pure and Applied Physics (and also, incidentally, optics.org), asked her editorial board whether the name of the journal should be changed to something shorter and, er, snappier.

The responses - from some of the world’s most respected optical scientists - revealed fundamental differences in perception between the terms "optics" and "photonics". Or, as Massimo Santarsiero of the University of Roma Tre put it: "This just confirms that not all of us agree on the meaning of the words optics and photonics, and surely misunderstandings of this kind would be unavoidable in the whole community of opticists (... sorry!)".  Nikolay Zheludev of the University of Southampton in the UK delved into the etymology of the words to try to tease out their true meaning:

• The Greek term όptικά (optics) referred specifically to matters and instruments of vision. Strictly speaking optics is the science of vision.
• Photonics derives from the Greek photon (fοtον), which means light. Photonics is the science of light.

"In my view, this implies that optics is a much narrower term than photonics," he concluded. "In fact, photonics embraces optics." But Lifeng Li of China’s Tsinghua University along with several other respondents, had a very different view: "To me the term optics in the modern and broad sense means the science and technology that deals with light, and photonics is a subdiscipline of optics."

Meanwhile, Mark Stockman at Georgia State University argues that names such as optics and photonics are just tags, and their meaning does not always correspond to their linguistic roots. "Optics is conventionally used for the general science of light," he said. "Photonics was originally introduced as a counterpart of electronics - using photons instead of electrons to process and transfer signals and information - but now the meaning of photonics is gradually becoming wider."

Naturally, we’d like to know your views. Can "photonics" be used interchangeably with "optics", or do they have quite distinct meanings? Please let us know what you think by using the commenting tool at the bottom of this article.

About the author

Susan Curtis is editor of optics.org.