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KOREKSI BENTUK BERKAS CAHAYA LASER DIODA MENGGUNAKAN LENSA SILINDER Ahmad Fauzi; Minarni '
Komunikasi Fisika Indonesia Vol 11, No 8 (2014)
Publisher : Universitas Riau

Diode laser is kind of laser which uses semiconductor material as the gain medium. Diode laser is preferred insome applications because it is less expensive, compact, available in wide range of wavelength and power.Unfortunately, diode laser also has some disadvantages compared to other types of laser. The material shape oflaser diode produces unsymmetrical beam shape whereas most laser applications need a circular beam.Correction of the beam shape can be done using some optics such as anamorphics prism pairs, cylindrical lenspairs and optical fibers. In this study, the beam shape of two diode lasers are corrected by a pair of cylindricallens and measured using a photodiode and CCD camera. The first diode laser is a coherent 830 nm diode whichhas beam size in x and y axis respectively 0.65 mm, 1.35 mm. The second diode laser is aixiz 638 nm diodelaser which has beam size in x and y axis respectively 1.34 mm, 3.67 mm. The first diode laser was bestcorrected using a pair of cylindrical with a focal length of 75 mm and -12.7 mm, the distance between the lens is7.15 cm which produced beam size in x and y axis respectively 1.38 mm and 1.51 mm. The second diode laserwas best corrected using a pair of cylindrical lens with focal length 95 mm and -19 mm, the distance betweenthe lens is 8.1 cm which produced beam size in x and y axis respectively 1.95 mm and 2.2 mm.

STUDI KELAYAKAN PENGGUNAAN SEL SILIKON SEBAGAI PENGUBAH ENERGI MATAHARI MENJADI ENERGI LISTRIK Walfred Tambuhan; Maksi Ginting; Minarni '
Komunikasi Fisika Indonesia Vol 10, No 7 (2013)
Publisher : Universitas Riau

Telah dilakukan penelitian tentang “Studi Kelayakan Penggunaan Sel Silikon sebagai Pengubah Energi Matahari menjadi Energi Listrik” dengan metoda eksperimen. Eksperimen dilakukan dengan cara merangkai dioda silikon selinder ke rangkaian bentuk paralel dan bentuk seri pada pelat rangkaian PCB, kemudian rangkaian dimasukkan kedalam suatu kotak terbuat dari kayu yang diisolasi dengan isolator kardus. Kotak tersebut ada yang dibuat terbuka tanpa pelat kaca dan ada yang dibuat tertutup dengan pelat kaca kemudian diletakkan ke tempat yang bebas cahaya matahari jatuh dengan mengarahkan dioda silikon tegak lurus terhadap cahaya matahari jatuh lalu diamati arus listrik yang dihasilkan dioda silikon setiap selang waktu 10 menit. Hasil yang diperoleh, arus listrik dihasilkan bernilai maksimum untuk dioda sambungan paralel dan terbuka tanpa penutup pelat kaca sebesar 102,9 x 10-2 milli ampere dengan energi listrik rata-rata yang dihasilkan 35,2 x 10-3 Joule pada temperatur 39oC sedangkan arus listrik minimum dihasilkan dari rangkaian dioda bentuk seri tertutup dengan pelat kaca sebesar 21 mikro ampere dengan energi listrik rata-rata dihasilkan sebesar 51 x 10-5 Joule. Dari hasik-hasil tersebut yang lebih bagus dan lebih layak digunakan untuk mengubah energi matahari menjadi energi listrik adalah dioda silikon bentuk sambungan paralel terbuka tanpa memakai penutup pelat kaca.

ANALISA PENGARUH PANJANG GELOMBANG SUMBER CAHAYA PENGINDUKSI FLUORESENSI TERHADAP FLUORESENSI KLOROFIL PADA DAUN BAYAM YANG DIPENGARUHI VARIASI SINAR MATAHARI Fitria Asriani; Minarni '
Komunikasi Fisika Indonesia Vol 12, No 10 (2015)
Publisher : Universitas Riau

Chlorophyll fluorescence imaging and spectroscopy can be used to detect early abnormalities on plants, which are caused by plant diseases, harsh environments, and intentional treatments. Development in chlorophyll imaging and spectroscopy which is economical, low cost, and portable are needed in attempts to explore fluorescence spectrum as markers for diseases and environmental stresses on plants. In this research, a fluorescence imaging system was built using LEDs with three variations in wavelengths i.e. 450 nm; 525 nm; and 680 nm, and a 3 Mega Pixel CMOS camera. The LED light was used as an excitation beam to induce chlorophyll fluorescence of spinach leaves. Relation between the LED wavelengths and the fluorescence intensities of the spinach leaves were investigated. The samples were Spinach leaves from Amaranthus tricolor Spinach plants grown under two variations of sunlight intensities. Two variations of the intensities were about 90% using plastic as the cover and 40% using plastic plus paranet. Relation between the sunlight intensity and fluorescence intensity was also investigated. The fluorescence intensity of the leaves were measured from RGB plot using Image-J software. The research results show that fluorescence intensity of the samples without paranet were higher than those using paranet. This is possibly caused by chlorophyll contents which is higher on plants without paranet. The excitation wavelength that showed the highest different fluorescence intensity was 680 nm, which showed 6,3% the difference in fluorescence intensity using and without paranet while for other excitation wavelength were 0,4% and 1,7% for 450 nm and 525 nm respectively.

ANALISA PENGARUH INTENSITAS SUMBER CAHAYA PENGINDUKSI FLUORESENSI TERHADAP INTENSITAS FLUORESENSI KLOROFIL PADA DAUN BAYAM MENGGUNAKAN METODE FLUORESCENCE IMAGING Minarni '; Iswanti Sihaloho
Komunikasi Fisika Indonesia Vol 12, No 10 (2015)
Publisher : Universitas Riau

Chlorophyll fluorescnce imaging and spectroscopy has been developed intensively during last decade to detect early symptoms of plant diseases and effects of environtmental stresses on plants. An economical, portable, and remote sensing system is needed for those purposes. In this research, a fluorescence imaging system was built using a LED with 465 nm wavelength, some neutral density filters and a 3 Mega Pixel CMOS camera. The intensities of LED light were varied using 5 different optical densities of the neutral density filters which were represented by their optical power after filtered 5,0 mW; 3,3 mW; 2,0 mW; 1,5 mW; and 0,7 mW respectively. This system was used to investigate the relation between the intensity of LEDs as a fluorescence inducer and the fluorescence intensity of spinach leaves grown under two variations of sunlight intensity. The variations were about 90% using plastic cover and 40% using plastic plus paranet cover. The spinach plant was Amaranthus tricolar varitas. The differences between chlorophyll fluorescence intensity of the spinach leaves for both treatment were also investigated. The fluorescence intensities were found from RGB plot using ImageJ software. The reseach results showed that intensity of LED light influenced the fluorescence intensity resulted on the spinach leaves. The higher the intensity of LED, the higher the fluorescence intensity. The spinach leaves grown without paranet provided higher fluorescence intensity however, the difference between both treatments was seen higher when LED intensity was the lowest which was about 41,6% difference.

SISTEM OPTIK INTERFEROMETER MICHELSON MENGGUNAKAN DUA SUMBER LASER UNTUK MEMPEROLEH POLA FRINJI Yayuk Widamarti; Minarni '; Maksi Ginting
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Wavemeter could be built using an interferometer with two laser sources. In this study, Michelson interferometer was built using two lasers which were He-Ne laser and diode laser. Characteristics of its fringe pattern were analyzed based on the laser power and beam size. The results showed that fringe pattern for laser He-Ne was obtained at arm length 12.5 cm x 12.5 cm with the beam height from optical table of 11.7 cm. He-Ne laser used was 632.8 nm in wavelength with the 5 mW power made by Meredith instrument. The diode laser had wavelength 650 nm with the power of 5 mW made byRoithner. The output of He-Ne laser from the interferometer system had 0.3 mW, diode laser by 0.5 mW. The best fringe pattern for both lasers was with visibilities rangedfrom 0.63 and 0.098, and beam width of each laser of 4.11 mm for He-Ne laser and 4.30 mm x 4.26 mm for diode laser.

PENGUKURAN NILAI PANJANG KOHERENSI DUA SUMBER LASER MENGGUNAKAN INTERFEROMETER MICHELSON Dhiesta Anggrainie; Minarni '; Tengku Emrinaldi
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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One of the laser beam unique properties is its coherence. Each lasers has different coherence length. The coherence length of laser is very important in many photonic applications such as holography, spectroscopy, and interferometry. The coherence length can be measured by an interferometer. Measurement of coherence length of two HeNe lasers and two diode lasers has been done using a Michelson interferometer. Two HeNe lasers with same wavelength but from the different company and two diode lasers with different wavelength and brands were used. The laser used were HeNe laser 632,8 nm by Griffin (laser I), HeNe laser 632,8 nm by Pudak (laser II), diode laser 638 nm(laser III) and diode laser 405 nm (laser IV). Interference fringes from interferometer were recorded by a Thorlabs CCD camera and processed using ToupView software to determine the respective value of the maximum and minimum intensity of each fringe pattern. Data of the fringe pattern intensity were used to calculate the visibility (V) and coherence length (Lc) of the lasers. The results showed that Lc and deviation of laser I was (1,12±31,8× 10−3) mm, laser II was (0,99±61,6× 10−3) mm, laser III was(0,50±2,9× 10−3) mm and laser IV was (0,3 8±4,8× 10−3) mm, respectively . The results also showed that the coherence lengths of the HeNe lasers were greater than the diode lasers.

ANALISIS FENETIK TANAMAN KARET (Hevea brasiliensis (Willd. ex A. Juss) Mull. Arg.) BERDASARKAN PENANDA ISOZIM DI LIMA KABUPATEN SENTRA PERKEBUNAN KARET RIAU Ivo Mayasari; Fitmawati '; Minarni '
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Many kinds of rubber plants (Hevea brasiliensis (Willd. ex A. Juss) Mull. Arg.)has been cultivated in Riau Province. Phenetic analysis of rubber plants can giveinformation about their relationship. Study to obtain information about the relationshipamong rubber plants which are grown in 5 rubber plantation centers in Riau wasconducted based on isozyme markers. A total of 15 trees had been studied. The sampleswere taken from 5 regencies i.e. Bengkalis, Meranti, Kuantan Singingi, Kampar, andRokan Hulu using an exploration method. Four enzymes (PER, EST, ACP, and AAT)were used for similarity and clustering analysis using NTSys program version 2.02. Theresult of this research showed 19 polymorphic bands, 9 bands from PER, 5 bands fromEST, 2 bands from ACP, and 3 bands from AAT enzyme. The similarity analysis of 15individuals showed that the similarity coefficient ranged from 0.47-1. The clusteringresult showed that all of individuals were grouped at the coefficient of 0.59. Most of thesamples were grouped together based on the band similarity. However, all of samplescollected from Bengkalis, as well as Kuantan Singingi, formed a cluster due to the highband similarity.

RANCANG BANGUN SISTEM DETEKSI POLA FRINJI UNTUK INTERFEROMETER MICHELSON Eka Buanti; Minarni '; Walfred Tambunan
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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Instrument used to precisely measure the wavelength of a laser light is known as a wavemeter. One of very important wavemeter parts is a fringe counting circuit. In this research a fringe counting circuit has been built and characterized using a Michelson Interferometer. The circuit system contained three parts i.e a current to voltage converter circuit for a photodiode, a TTL converter circuit, and a counting circuit. The circuits were characterized using two He-Ne laser with two different laser powers 1 mW and 5 mW which were used as the light source for a Pasco Michelson Interferometer. Two photodiodes with two different sensitive areas 100 mm2 and 7.5 mm2 were used. The research results showed that 1 mW Pudak He Ne laser resulted 2 µA for dark fringe and 8 µA for bright fringe when using 7.5 mm2 photodiode active area, then 3 µA for dark fringe and 400 µA for bright fringe when using 100 mm2 photodiode. The results for Meredith He Ne laser resulted 2 µA for dark fringe and 14 µA for bright fringe when using 7.5 mm2 photodiode, then 50 µA for dark fringe and 8000 µA for bright fringe when using 100 mm2 photodiode. The I toV converter which was designed produced voltage bigger than 5 V when using 100 mm2 photodiode. The counter circuit resulted 3.2 V TTL signal output for 200 mV TTL signal input with the same frequency.

ANALISA SPEKTRUM DAN PANJANG KOHERENSI BEBERAPA JENIS LAMPU MENGGUNAKAN SPEKTROSKOP PRISMA DAN INTERFEROMETER MICHELSON Maria '; Minarni '; Walfred Tambunan
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 2, No 1 (2015): Wisuda Februari 2015
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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There are three types of commercial lamps available today which are incandescent lamp (light bulb) , fluorescent lamp or Compact Fluorescent Lamp (CFL), and Light Emitting Diode (LED). The three types of lamps can be distinguished by some aspects such as their efficiency, color spectrum, and coherence. This research aimed to obtain and differentiate the color spectrum and coherence of the three kind of lamps. The spectrums were obtained using a prism spectroscope while the coherence levels were analyzed using a Pasco Michelson interferometer. The samples were the three types of lamps with the same power of 5 Watt and CFL lamps with three different power of 5 Watt, 26 Watt, and 45 Watt. The spectrum and fringe pattern of the lamps were captured using a CCD camera and processed by imageJ software. The research results showed that the color spectrum of light bulb and LED produced a continuous spectrum. While the light of light bulb was dominant at red color and LED light at blue color. CFL light spectrums were partly continuous and dominant also in blue color. The different power of CLF produced different brightness, however the spectrum was still dominant in blue. Coherence of the three type of lamps was different as shown in the fringe pattern obtained. CFL produced fringe pattern with high visibility which showed higher coherence than that of LED and light bulb.

ANALISA PENGGUNAAN LENSA SILINDER UNTUK MENGUBAH BENTUK BERKAS LASER DIODA MENJADI BENTUK GARIS Muhammad Mashuri; Minarni '; Sugianto '
Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam Vol 1, No 2 (2014): Wisuda Oktober 2014
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Matematika dan Ilmu Pengetahuan Alam

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A research on the application of cylindrical lenses to change beam shape of diode lasers from eliptical to line shape has been conducted. The beam characteristic of the lasers before and after using the lenses were analyzed by a calibrated photodiode and a CCD camera. The distance between CCD camera and the lenses were also varied to obtain the optimal length of the line. The diode lasers used were λ=830 nm Coherent diode laser with beam size 0,6 mm and 0,9 mm in x and y axis and λ=638 nm Aixiz diode laser with beam size 1,2 mm and 1,6 mm in x and y axis were used. Three cylindrical lenses with three different focal length were used whice were 50 mm, 75 mm, and 95 mm respectively. The results showed that the maximum line lengths (L) of λ=830 nm diode laser were 1,86 mm, 2,55 mm, and 1,39 mm respectively. For the λ=638 nm diode laser the maximum line length (L) were 3,74 mm, 4,32 mm, and 3,87 mm respectively to the same focal length. The result also showed that the bigger λ produced the shorter line (L) than the smaller λ. For the biggest focus need the longest distance (z) to produce the longest line.

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