We use a Fabry-Perot cavity to optically filter the output of a Ti:sapphire frequency comb to integer multiples of the original 1 GHz mode spacing. This effectively increases the pulse repetition rate, which is useful for several applications. In the case of low-noise microwave signal generation, such filtering leads to improved linearity of the high-speed photodiodes that detect the mode-locke...

Silver films of 40 nm thickness, evaporated on a 300 nm thick low-stress silicon nitride layer, are used as high-quality mirrors operating in the visible and near IR spectral range. Using a silicon nitride membrane under tension, within a square Si frame after bulk micromachining, improves the initial mirror flatness. Two parallel mirrors, with square aperture of up to 2x2 mm and an electrostat...

We report, for the first time to our knowledge, an all-fiber wavelength-swept Tm-doped laser based on a fiber Fabry-Perot tunable filter in the 2 μm spectral region. The laser wavelength can be continuously tuned over 200 nm from 1840 to 2040 nm in a short period of time. The demonstrated tuning speed was 12.5 μm/s with a tuning efficiency of 17.5 nm/V. The spectral linewidth of the laser was m...

The supermode noise suppressing ratio (SMSR) and the phase noise of a harmonically mode-locked Erbium-doped fiber laser (HML-EDFL) with an intra-cavity semiconductor optical amplifier (SOA) and an optical band-pass filter (OBPF) are improved and compared with a state-of-the-art Fabry-Perot laser diode (FPLD) injection-mode-locked EDFL. By driving the intra-cavity SOA based high-pass filter at u...

We present the design of a harmonic resonant filter that can be used with a Fourier transform spectrometer (FTS) for simultaneous measurement of a series of lines in the CO rotational ladder. To enable studies of both broad CO absorptions in Venus and modestly red-shifted CO emission from external galaxies, relatively broad (approximately 10-30-GHz FWHM) transmission passbands are desirable. Be...

The main objective of this study is to develop a near-infrared (NIR) tunable external cavity laser (ECL) that is based on a semiconductor optical amplifier and two different wavelength selective elements. In order to achieve the wavelength selection, several filters have been tested in the ECL setups, including plasmonic filter, acoustooptic tunable filter (AOTF), gradient photonic crystal and ...

We report on the generation of a type-I multimode two-photon state on a rubidium D(2) line (780 nm) using periodically poled KTiOPO(4) crystals. With a degenerate optical parametric oscillator far below threshold, we observe an oscillatory correlation function; the cross correlation between two photons shows a cavity bandwidth of about 7.8 MHz. We also use a Fabry-Perot etalon to filter its mos...

We propose and numerically analyze a plasmonic Bragg reflector formed in a graphene waveguide. The results show that the graphene plasmonic Bragg reflector can produce a broadband stopband that can be tuned over a wide wavelength range by a small change in the Fermi energy level of graphene. By introducing a defect into the Bragg reflector, we can achieve a Fabry-Perot-like microcavity with a q...

A resolution enhancement technique for optical microlithography based on coherent multiple imaging was investigated with use of Prolith/2 (a commercial lithographic simulation tool). It was shown that a Fabry–Perot etalon placed between the mask and the projection lens of an optical stepper could be interpreted as an appropriate transmission-phase pupil-plane filter. While previous calculations...

A simple and robust system is presented to generate wavelength-tunable optical short pulses by use of two gain-switched Fabry-Perot laser diodes in a mutual pulse injection-seeding scheme. The operating wavelength of the optical pulses is flexibly selected by adjustment of a tunable filter, and its intensity is enhanced with an erbium-doped fiber amplifier. The side-mode suppression ratio achie...