Application of lensed fiber collimator to miniature CWDM filter device

Abstract

are formed strongly on both side of the patch antenna, which means that this frequency depends on the three stubs and horizontal size of the patch antenna. The normalized radiation patterns of the antenna are shown in Figure 6. At 218, 338, and 400 GHz, the half-power beamwidths of the co-polarization were 144.0 , 122.4 , and 118.6 in E-plane and 88.3 , 71.3 , and 62.2 in H-plane, respectively. Cross-polarization at all frequencies is less than À10 dB. Gain is 1.61, 1.08, and 4.68 dBi and directivity is a 6.29, 6.92, and 7.43 dBi, respectively. Radiation efficiency is 34, 26, and 53%, respectively. The patch antennas rely on fringing fields for radiation and its efficiency is strongly dependent on the patch size to the dielectric layer thickness ratio [3]. The performances of the proposed antenna are summarized in Table 2. It is important to note that the directivity of the proposed patch antenna was improved by 1.79 dBi at all frequencies compared to a previous study used differential patch antenna [12]. CONCLUSIONSThe performance of the multiband THz antenna is successfully demonstrated using a finite-difference time-domain method. The antenna was designed by using stubs and slot-type SRR, which make it possible to detect multi-frequencies with a small-sized antenna. The proposed antenna was proven to meet the requirements for THz CMOS multiband camera design by reviewing return loss, À3dB impedance bandwidth, half-power beamwidth, and antenna gain at the selected three-bands of 218, 338, and 400 GHz, respectively.Fully integrated with CMOS detector element compatible to implement a large array at low cost, the proposed miniaturized multiband on-chip antenna is expected to be actively used for real-time multi-frequency imaging systems in THz band.

Breath sensor based on reflective optical lensed fiber

“…The work presented here deals with the possible utilization of optical lensed fiber structure for breath sensing probe. In an earlier work, we have demonstrated the lensed fiber as a tiny optical collimator [15–17] and as a CWDM device [18]. Here, an experimental study of the optical lensed fiber to work as a breath sensor is demonstrated for the first time.…”

“…The gradient constant g is 3.8 mm −1 so the quarter‐pitch of a GIF tip is 413 μm in theorem. In terms of the best collimation and minimum divergence angle, the optimum lensed fiber was about 446 μm in our previous work [18]. The SMF with 10 μm core diameter and 125 μm cladding diameter provided by Corning was spliced to GIF.…”

Low Cost Refractive Index Sensor Based on Optical Lensed Fiber

“…Though, gratings, tapering, and metal‐coated SPR have been used as highly sensitive RI sensing devices, the complex fabrication process increases the difficulty and the device cost for mass production. In an earlier work, we have presented a lensed fiber as a tiny optical collimator and as a CWDM device . In this article, we propose for the first time to the best of our knowledge, an RI sensor based on an optical lensed fiber.…”

Enhancement of Surface Wettability by Intra-Helium Plasma for Liquid Core Fiber Lens

“…Recently, the authors have reported a preliminary study of helium APP's effects over the inner surface of a silica hollow optical fiber with the hole diameter of ∼100μm using a conventional set-up [15], where it was found that the liquid curvature inside HOF was changed by APP. Flexible control of the radius of curvature of the liquid core would find several applications in optical imaging and trapping [16]- [18], yet detailed investigation on this potential in liquid core fiber optics has been very limited.…”