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DEVELOPMENT AND EXPERIMENTAL CHARACTERIZATION OF AN IOT-CONTROLLED RGB LED LIGHTING SYSTEM FOR HYDROPONIC APPLICATIONS
(2026-01-01)
Worsoongnern, S.
;
Yindeesuk, W.
;
Kamoldilok, S.
;
Srinuanjan, K.
;
Limsuwan, P.
This study presents the development of an Internet of Things-based RGB LED lighting system for precise, flexible light control in hydroponic plants. The system consists of 480 high-power RGB LEDs controlled by an ESP8266 microcontroller, enabling real-time adjustment of light intensity, photoperiod, and color ratios via a smartphone. Pulse-width modulation duty-cycle modulation enables the generation of white light suitable for different stages of plant growth. Experimental results show a linear correlation between illuminance and duty cycle for all color channels. Spectral analysis confirms stable emission within the photosynthetically active radiation range (400–700 nm), with the spectral composition remaining unchanged even when brightness is reduced (dimming). The system demonstrates high control accuracy and adaptability for regulating plant growth lighting, particularly for leafy vegetables such as lettuce.
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Ultrawide-range refractive-index sensor based on asymmetric integrated Y-junction optical waveguide
(2023-01-01)
Phongwisit, P.
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Kamoldilok, S.
;
Limsuwan, P.
;
Srinuanjan, K.
We present a novel ultrawide-range refractive index (RI) sensor based on an asymmetric Y-junction optical splitter. A cylindrically shaped rod with a diameter of 350 nm and a height of 1000 nm with a different RI is inserted into a junction of the asymmetric Y-junction waveguide. This rod serves as a sensing area. Our sensor is simulated using a finite-difference time-domain technique. The splitting ratio is studied for the cases of two operating wavelengths, 1480 and 1550 nm. The results show that the splitting ratio can be described as a parabolic function of the RI of the sensing area at both operating wavelengths. An approximately linear relationship between the splitting ratio and the RI occurs in a narrower RI region of 1.00–1.50, thus enabling to design an ultrawide-range RI sensor. The sensor sensitivities at the wavelengths 1480 and 1550 nm are equal respectively to 0.2653 and –0.4908 RIU–1, with the corresponding R2 parameters amounting to 0.9889 and 0.9777. Our device can serve as an ultrawide-range optical RI sensor for identification of micro-scale biochemical or chemical specimens.
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360 degree white light holography display on surface of transparency conical cup
(2021-01-01)
Srinuanjan, K.
;
Kamoldilok, S.
This paper presents the method and experimental results of the construction and reconstruction of three dimensions conical holography. He-Ne laser is used as the construction light source. Then the construction light is shone on top of a transparency conical cup, where a plain holographic film is wrapped around and attached to its surface. The object is located at the bottom of the cup. In this manner, the cup acts as a captured screen. After exposure, the film is developed and fixed by a chemical solution. The three-dimensional holography is recorded in the film. For reconstruction, we used red LED and flashlight as a reconstruction light source. The film is wrapped around and attached to the surface of the cup again. When the reconstruction light shines on the cup, the three-dimensional holography appears in the center of the cup. The cup is rotated in step, each step is 45 degrees, and the image is recorded by the digital camera. Experimental results show that the 360 degrees three-dimensional holographic image is successfully reconstructed. In conclusion, we could apply the method to create a three-dimensional holographic for displaying in all directions.
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Analysis of effective numerical aperture in 2-D photonic crystal waveguide
(2014-01-01)
Chantakit, T.
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Kamoldilok, S.
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Srinuanjan, K.
;
Yupapin, P. P.
The effective numerical aperture calculation in two-dimensional Photonic crystal waveguide has been proposed. In this paper we present the analysis of ray optics refracted inside nano rods and at the boundaries between rods, which separates rod gap is much smaller than the incident wavelength assumed to reflect on the region. In operation, the resolving numerical aperture was compared with the finite difference time domain method via OptiFDTD software. Although numerical aperture mentioned above was found to be extremely close to fiber optics, a transmission passes though compartments of the rods are observed due to significant estimation of transmission and reflection of electric field. The compared simulation results will be discussed. By the aforementioned is that in the near future we will modify wave equation in periodic media of waveguide structures reached to the transverse electric equation of beam propagation in the two-dimensional Photonic crystal waveguide analysed. © (2014) Trans Tech Publications, Switzerland.
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Micro stirling engine controlled by light
(2011-01-01)
Pipatsart, S.
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Kamoldilok, S.
;
Yupapin, P. P.
This paper proposes a new technique for a micro Stirling engine operation using leaky light resonant or whispering gallery modes (WGMs) in a nano-waveguide, in which the nano-waveguide is designed and configured by a nanoring resonator. By using the Optiwave programming based on Finite Difference Time-Domain (FDTD) method, an InGaAsP/InP nanoring resonator was designed and simulated. The simulation results obtained have shown that the leaky light resonant modes can be controlled by the ring radius variations, whereas the maximum resonant peak of nanoring resonator is occurred at the inner and outer ring radii of 0.775 and 1.55 μm respectively. The maximum peak intensity of the nanoring resonator is 12000 W/m2. Finally, the use of leaky light mode resonant peak of the center nanoring resonator for micro-Stirling engine is discussed in details. © 2011 Published by Elsevier Ltd.
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A self-calibration nano-scale sensing transducer using PANDA ring resonator
(2010-12-01)
Srinuanjan, K.
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Tipaphong, W.
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Kamoldilok, S.
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Yupapin, P. P.
We propose a new system of self-calibration measurement using a nano-scale sensing transducer, which is known as a PANDA ring resonator type, whereas the sensing unit is combined into the system by mean of one ring, and the other ring is set as a reference signal. We use the method of finite difference time domain (FDTD) via the computer programming called Opti-wave to analyze and simulate. The simulation result has shown that we can use this system for high-precision and self-calibration measurement using a nano-scale sensing transducer, whereas the measurement resolution of 1 nm can be obtained. The recovery and the reciprocal signals can also be formed, which can be used to approach to many advantages of measurements, including the possibility of standardizing measurement accuracy. ©2010 IEEE.
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A new concept of cold atom using fast optical tweezers
(2010-01-01)
Jakgoljun, B.
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Srinuanjan, K.
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Kamoldilok, S.
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Yupapin, P. P.
We propose a new concept of a cold atom generation using a tiny optical device system. A system consists of a multi-stage nonlinear micro-ring system incorporating an add/drop filter, which the storage unit can be formed the fast tweezers and the cold atom concept presented. In operation, the optical tweezers can be generated by using a Gaussian pulse input into the microring system, where the amplified and tuned optical tweezers using a light pulse propagating within an add/drop filter. By using the suitable parameters such as ring radii, effective areas, coupling coefficients and refractive indices, an atom/particle can be trapped by the specific optical tweezers and propagating within a storage ring. Results obtained have shown that the fast tweezers time is approached the negligible value, where the terms of time independent motion of atom/particle can be performed by using the fast tweezers, and the cold atom concept is obtained. In application, such a technique can be used to form the similar manner for molecule, DNA, photon, or Ion, where the memory unit of them can be formed, which will be available for a hybrid memory or computer in the near future.

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