• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.11
• /
• pp.26-35
• /
• 2007

We characterized the properties of the fabricated filter with the total internal reflection mirror (TIR) in the rectangular ring resonator and very small multimode interference (MMI) couplers on an InP material platform for photonic integrated circuits. Coupling power in and out of a resonator is increased by using an optimum MMI length of 110 ${\mu}m$ and a width of 9 ${\mu}m$, respectively. The semiconductor optical amplifier with the length of 120 ${\mu}m$ is integrated in the resonator to compensate the loss of the internal waveguide and the TIR mirror. A free spectral range of approximately 2 nm (244 GHz) is observed with an on-off ratio of 13 dB. The curve fitting also yields the power coupled per pass as 42%. To reach critical coupling at this coupling level would require a round trip loss of about 2.4 dB.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.6
• /
• pp.411-416
• /
• 2020

An optical arrangement has been set inside a photo-spectrometer to measure the reflectance of IR optics materials in mid IR range. The optical arrangement consists of equally spaced 4 gold coated full reflecting mirrors with the incidence angle of 45°. Baseline beam intensity I_B has been measured while the beam proceeds through the 4 mirrors. Reflectance of a mirror has been estimated from the I_B. And the beam intensity I_S with the specimen in the optical path has been measured with the 4th mirror replaced with the specimen. Reflectance of the specimen has been estimated from the value of I_S/I_B. Then the estimated reflectance has been put in Fresnel equation relating reflectance and refractive index(RI) to estimate the RI of the material. Measurement has been made for sapphire, germanium, magnesium fluoride, and zinc sulfide. The estimated RI of the materials are closely matching with reference data and the maximum difference less than 2% over the wavelength range 3-5㎛ for all materials tested. As an FT-IR photo-spectrometer with a broadband wavelength infrared light source is used, this method has the advantage of measuring the refractive index at multiple wavelengths in a single measurement.

• The Journal of Natural Sciences
• /
• v.8 no.1
• /
• pp.23-26
• /
• 1995

Operating characteristics of a $Cr^3+$:LiASF laser pumped by 640 nm and pulsed DCM dye laser are observed. The laser consists of a 93% reflectivity of half mirror and a total reflector, and the length between two mirrors is 3cm. Maximum efficiency is 10% for 22 mJ of pumping energy and the maximum slope efficiency is 19%.

• Korean Journal of Optics and Photonics
• /
• v.28 no.5
• /
• pp.229-235
• /
• 2017

A widely tunable U-shaped SGDBR (Sampled Grating Distributed Bragg Reflector) laser diode is designed and analyzed by means of a time-domain simulation. The U-shaped SGDBR laser diode consists of SGDBR, active, phase, and TIR (Total Internal Reflection) mirror sections, so the coupling losses across the sections should be carefully considered. The tuning range of the designed U-shaped SGDBR laser is about 1525-1570 nm, which is confirmed by the simulation. The simulation results show that the loss in the TIR mirror region should be less than about 2 dB, and the refractive-index difference at the butt coupling between the passive and active regions should be less than 0.1, to provide the complete tuning range.

• Smart Media Journal
• /
• v.12 no.1
• /
• pp.102-111
• /
• 2023

As one of the image symbols, the second frame has rich symbolic metaphor. In previous studies, second frames are mostly presented in physical forms such as doors, windows, but in <The Power of the Dog>, there are various forms of second frames, providing more types for the study of second frames. Panofsky's Iconology has put forward a rigorous research method on how to interpret the meaning of image symbols in the picture. This study aims to use Panofsky's Iconology to analyze the second frame in <the Power of the dog>. The purpose is to expand the methodology of film image research and break through the problem that the Iconology analysis of film image stays in narrative analysis (iconographical analysis). It can be seen from the results of this study that the second frame has different visual presentation according to the requirements of narrative. In the narrative of the film, it symbolizes the depressed tone of the film and the stressful relationship between different characters. What director Campion wants to show through the second frame is that in the film industry where the problem of women is getting better, the motif of feminist film creation has changed from the expression of female appeals in binary opposition to the expression of the appeals of diverse groups in "decentralization."