Dear Sara,

direct, in-situ detection of chemicals in aquatic environment is definitely required and becoming more common.

I don´t know about fiber optics in this context, but any means of optical, chemical, electircal or physical detection are attractive.

There is already a rather big variety of chemical sensors available on the market.

Yes, there were various types of chemical sensors since many years ago. Although existing chemical sensors have good performance but I think fiber optic chemical sensors have unique properties like remote and online sensing, low working temprature (usually room temprature), immunity to electromagnetic noise and etc. and by developing the optical technology cost of optical sensors will be decreased.

On the other, I think in many applications we're going to replace electronics with optics and photonics. In the future maybe we'll want to do this for chemical sensors!

What's your opinion?

Hi Sara. I think you are right. Overall optical solutions are important for detection of chemicals in the environment.

From my perspective, any reliable, well-communicating and reasonably-priced (chemical) sensors would be attractive. Cost-effective instruments would mean better understanding of the environment.

I am not an expert on optical circuits, but I guess if electronic components can be replaced by optical circuits there will be certain benefits.

What is the tolerance of optical circuits e.g. in terms of temperature, and would those circuits consume less power than conventional circuits do?

Hi Harri

At first I want to appreciate for your nice comments.

Optical circuits are very low power circuits and they are much faster than electrical circuits. Actually they work at light speed. But one of the biggest problems is their size. They have still micron or even millimeter size. Today integrating the opitcal circuits is one of the most important branches in optical technologies.

It all depends what is the data rate and transmission spans you want to achieve in optical fibres regardless of the type of the material. Various types of fibre optics are used. Standard single mode fibre is the most common of them all specially in terms of cost it is used more frequently. It certainly will be interesting to see if the cheaper martials will be able to reduce the fibre attenuation even further (currently it is 0.2 dB/km for SMF).

Sara,

Your question is interesting.

Sensors play an important role in acquiring the properties of the physical world.  They have many applications in many branches of our life. Senors are devices that convert the nonelectrical quantities into electrical quantities where they can be easily processed, displayed and stored.

in case of the optical fiber chemical sensors, the sensed material is made to substitute the clad or to intercept the light ray in the fiber. In this way the light beam will be reflected or absorbed in the material to be detected. The reflection coefficient and or the absorption coefficient is a characteristic of the material to be detected.

So. in principle, the fiber optic sensors is based on the optical effects of light on the material to be detected and the differing behavior of these materails on   light.

Concerning the speed of detection, one has to take into consideration not only the propagation time but the detection speed. In practice the detection speed determines the speed of the sensors.

In any detection system, the electronics is a fundamental part in it. Tell me how do you generate the light and how do you sense it .

I think you can miniature your detectors by using planar wave guides.

For more information please see the review paper in the link:

 www.mdpi.com/1424-8220/12/12/16522/pdf

wish you uccess

Yes...the future is bright for FOCS. My personal opinion is that one cannot ignore FOS (Fiber Optic Senssors)..because all of the advantages of FOS...especially multipoint sensing. I think now the time has come to standerdize the FOS..so that their utilization will increase and the cost will come down. isn't it?