KAJIAN KOMPUTASI NUMERIK MODEL INTEGRATIF PADA DIFRAKSI CELAH LINGKARAN MENGGUNAKAN METODE PENDEKATAN SIMPSON 1/3

Abstrak Telah dilakukan penelitian tentang komputasi numerik model integratif pada difraksi celah lingkaran dengan tujuan untuk menerapkan metode simpson 1/3 untuk mencari solusi kasus difraksi celah lingkaran, menghitung nilai integrasi bessel menggunakan metode simpson 1/3, menentukan jarak antara dua intensitas pada pita terang, memperoleh grafik pola intensitas cahaya terhadap jarak pada kasus difraksi celah berbentuk lingkaran. Hasil integrasi yang diperoleh dengan metode simpson 1/3 pada tiga titik puncak intensitas yaitu 0.14352548, -0.3342371, 0.27050545 Dari hasil perhitungan pada puncak pertama untuk intensitas maksimum pada terang pusat yang berada pada jarak 0.3 cm dengan nilai intensitas 0.91553621, puncak kedua pada jarak 5.1 cm dengan nilai intensitas 0.01718022 dan pucak ketiga pada jarak 8.6 cm dengan nilai intensitas 0.00395745. Dari hasil perhitungan diperoleh grafik antara jarak dengan intensitas sehingga terdapat pola yang membentuk cincin gelap terang semakin besar panjang gelombang sumber maka semakin besar pula jarak antara suatu titik intensitas dari intensitas maksimum. Hasil perhitungan menunjukkan bahwa pendekatan integrasi simpson 1/3 hampir mendekati hasil yang telah diperoleh secara analitik. Dari hasil ini dapat dihitung nilai error dari program terhadap nilai eksak secara analitik dan diperoleh nilai pendekatan yang kecil yaitu -7.95 x 10-6, -6.07 x 10-6, 2.25 x 10-6. Sehingga hasil pendekatan dengan metode Simpson dapat diterima serta dapat dikatakan bahwa program yang dibuat telah berfungsi dengan baik. Kata kunci: Bessel; metode Simpson 1/3; difraksi celah lingkaran. Abstract [Numerical Computation Study Of Integrative Models In The Circular Aperture Diffraction With Simpson 1/3 Approach Method] Research on numerical computation of integrative models on the circular aperture diffraction with the aim to apply the Simpson 1/3 method to find a solution to the circular aperture diffraction case, calculate the integration value of the Bessel using the Simpson 1/3 method, determine the distance between two intensities on the bright band, obtain graph of the pattern of light intensity versus distance in the case of circular slit diffraction. The integration results obtained by the Simpson method at three intensity peaks are 0.14352548, -0.3342371, 0.27050545 From the results of the calculation at the first peak for maximum intensity at the center of light at a distance of 0.3 cm with an intensity value of 0.91553621, the second peak at a distance of 5.1 cm with an intensity value of 0.01718022 and a third peak at a distance of 8.6 cm with an intensity value of 0.00395745. From the calculation results obtained by the graph between the distance with intensity so that there is a pattern that forms a dark ring of light the greater the source wavelength, the greater the distance between an intensity point from the maximum intensity. The calculation results show that the Simpson 1/3 integration approach is almost close to the results that have been obtained analytically. From these results, an error value from the program can be calculated analytically and the exact value of the approach obtained is -7.95 x 10-6, -6.07 x 10-6, 2.25 x 10-6. So the results of the approach with the Simpson 1/3 method can be accepted and it can be said that the program created has functioned well. Keywords: Bessel; Simpson 1/3methods; circular aperture diffraction.

New Technical Solutions in the Production Method of High-Aperture Ruled Diffraction Gratings

This paper presents a new approach in the production method of high-aperture diffraction gratings with high diffraction efficiency on convex and concave working surfaces with large deflection based on the use of an original pendulum-type ruling engine.

Analysis of wavefront effects for large-aperture tiled-grating compressor

Monolithic large-aperture diffraction grating tiling is desired to increase the output capability of multi-kilojoule petawatt laser facilities. However, the wavefront errors of input pulse and gratings will degrade the focal spot quality and the compressibility of the output pulse. In this work, the effects of wavefront error of input pulse, deformation and wave aberration of the grating for the large-aperture tiled-grating compressor are investigated theoretically. A series of numerical simulations are presented to discuss the changing trends of focal spot energy caused by wavefront error of input pulse and obtain the error tolerance for specific goals. The influences of coating stress and the wave aberration of holographic exposure gratings on the diffraction wavefront are also discussed. Some advice is proposed for improving the performance of large-aperture tiled-grating. This work paves the way for the design of practical large-aperture tiled-grating compressor for ultrahigh intensity laser facilities in the future.