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We have developed 40-Gb/s traveling-wave electroabsorption-modulator-integrated distributed feedback laser (TW-EML) modules using several advanced technologies. First, we have adopted a selective area growth (SAG) method in the fabrication of the 40-Gb/s EML device to provide active layers for the laser and the electroabsorption modulators (EAMs) simultaneously. The fabricated device shows that the measured 3-dB bandwidth of electrical-to-optical (E/O) response reaches about 45 GHz and the return loss (S11) is kept below -10 dB up to 50GHz. For the module design of the device, we mainly considered electrical and optical factors. The measured S11 of the fabricated 40 Gb/s TW-EML module is below -10 dB up to about 30 GHz and the 3-dB bandwidth of the E/O response reaches over 35 GHz. We also have developed two types of coplanar waveguide (CPW) for the application of the driver amplifier integrated 40 Gb/s TW-EML module, which is a system-on-package (SoP) composed of an EML device and a driver amplifier device in a module. The measured S11 of the two-step-bent CPW is below -10 dB up to 35 GHz and the measured S11 of the parallel type CPW is below -10 dB up to 39 GHz. [ABSTRACT FROM AUTHOR]

A system-on-packaging (SoP) with an electroabsorption modulator (EAM) for a 60 GHz band radio-over-fiber (RoF) link is described. The system consists of an EAM device, a microstrip filter, and a low noise amplifier (LNA). The microstrip filter was used to achieve impedance matching between the EAM device and the LNA and to reject the local oscillator (LO) frequency of the heterodyne system. The frequency response and the effect of the EAM bias voltage were measured for a simple RF/optical link. A 60 GHz band RoF link with 2.5 GHz intermediate frequency (IF) was prepared to measure the transmission characteristics of the 16 QAM data. [ABSTRACT FROM AUTHOR]

We manufactured a hybrid adhesive film capable of curable deoxidization by combining thermoplastics and thermosets. The generated acidic moieties on this hybrid adhesive film completely removed the oxide layer of various Sn-based metal solders and Cu, leading to electrical interconnection. The chemical structure, reaction rate, and glass transition temperature (Tg) of the films were examined via Fourier transform infrared spectroscopy and differential scanning calorimetry. The initial reaction rate of the hybrid deoxidizing adhesive films increased with increasing concentration of anhydride and phenoxy resin. Meanwhile, the reaction rate at the end for curing completion decreased as a function of anhydride and phenoxy resin. Tg of the films decreased with the increase in anhydride and phenoxy resin concentrations. The fabricated film resulted in complete wetting of the solder/Cu for electrical interconnection between semiconductor chips as a promising electronic application. This hybrid film can be useful for various applications requiring deoxidization and adhesion [ABSTRACT FROM AUTHOR]

An optical transmitter system-on-packaging (TxSoP) with an electro-absorption modulator (EAM) was developed for 60-GHz band rf with radio-over-fiber (rf/RoF) uplink. An analysis to develop the TxSoP with a small noise figure was performed so that the noise figure of the modified TxSoP decreased by 15 dB. The rf/RoF uplink with the modified TxSoP was established, and the error vector magnitude (EVM) and the signal-to-noise ratio (SNR) of the link were measured between 2.2% and 3.2% and between 26 dB and 29 dB from 140 MHz to 800 MHz, respectively. Digital CATV signals corresponding to 86 channels were transmitted through the link, and total throughput of the link was 2.6 Gbps. [ABSTRACT FROM AUTHOR]

We developed an analog optical transmitter module with rf gain for 60 GHz radio-over-fiber (RoF) application narrow band. It consists of an electroabsorption modulator (EAM), a filter, and amplifier. The frequency response increased about 20 dB from the noise level around 60 GHz with the EAM bias voltage of −1.6 V. The 3 dB bandwidth was about 2.2 GHz. The signal-to-noise ratio of the RoF link with transmitter module was measured and the noise figure was obtained, which were compared with those of narrow band EAM module with an additional amplifier. A 16 quadrature-amplitude-modulation data signal could be transmitted with the signal-to-noise ratio of 15.9 dB. The noise figure of the RoF link with the transmitter module was calculated 19.2 dB, which is about 7.5 dB larger than that of the EAM module with rf amplifier at the bias voltage −2.0 V. [ABSTRACT FROM AUTHOR]

We design and fabricate a traveling-wave electroabsorption modulator for RF/optic conversion. The RF gain is measured with a simple RF/optic link. It is related to the optical transfer curve. The input optical power causes the change of the transfer curve so that the RF gain varies accordingly. The RF/optic conversion gain shows a close relationship with the slope efficiency of transfer curve. Linearity is also one of the important characteristics for analog applications. We evaluate the linearity of the module from the 3rd-order intermodulation distortion (IMD3). © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1151–1155, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21564 [ABSTRACT FROM AUTHOR]

We developed an analog 60-GHz module for RF/optic conversion by using an electroabsorption modulator (EAM) device associated with a traveling-wave electrode. The impedance matching of the module was accomplished with the 30-Ω termination such that the resonance was precisely located at 60 GHz and the fractional bandwidth at S11 = -15 dB was as large as 1.0 GHz. The RF/optic conversion gain of the EAM device revealed a strong dependence on the input optical power and was closely related with the slope change in the optical transmission characteristic with reverse bias. From the EAM module with the composite-type multiple-quantum-well electroabsorption core consisting of both 8- and 12-nm quantum wells, we obtained the optimal RF/optic conversion gain at the reverse bias between 1.5–2 V in a wide range of input optical power from -6 to +9 dBm. In the same bias range, the third-order intermodulation distortion was <-49.5 dBc as obtained with RF input of -7.5 dBm. [ABSTRACT FROM AUTHOR]