We report a low loss strip loaded single mode waveguide with a GaAs/Al0.3Ga0.7As double heterostructure. The propagation loss is derived to be 1.3 dB/cm for 1.3µm single mode propagation from Fabry-Perot resonances of a waveguide with good cleaved facets using DFB laser.

We have developed an InP-based monolithic optical frequency discriminator consisting of a temperature-insensitive optical filter and dual photodiodes. This integrated device detects the optical frequency deviation of the input light as differential photocurrent from the dual photodiodes, and the photocurrent is fedback to the light source for frequency stabilization through a differential amplifier. The FSR and extinction ratio of the filter are 50 GHz and 20 dB. The total opto-electronic conversion efficiency is 40%. In a frequency stabilization experiment using the developed discriminator, the frequency fluctuation of a DFB laser was reduced to less than 10 MHz.

As one of the approaches to developing a monolithic integrated device, optical coupling efficiency between a monolithically integrated DFB laser and a passive waveguide is experimentally evaluated. A butt-joint coupling is selected in this study, because it is expected to produce a higher coupling efficiency than any other coupling techniques. The DFB laser is butt-jointed with the waveguide by a low-pressure MOVPE selective growth, which produces no overgrowth at the butt-joint region. The average efficiency is evaluated to be 60%. The distribution of the evaluated efficiency indicates that the coupling efficiency of more than 50% can be obtained with good reproducibility.

A test structure and method for two-dimensional analysis of fabrication process variation of MOSFET using a photoemission microscope are presented. Arrays of 2010 (=200) MOSFETs were successfully measured at a time and evaluated the fluctuation of their characteristics. The fluctuation of hot-carrier-induced photoemission intensity was larger as gate length becomes smaller. Although the intensity fluctuation of photoemission in the same MOSFET was within small range, the fluctuation all over the MOSFET array was relatively large and independent of the position in the array. An estimation method of the gate length fluctuation has been demonstrated with the photoemission intensity distribution analysis.

We have developed an InP-based monolithic optical frequency discriminator consisting of a temperature-insensitive optical filter and dual photodiodes. This integrated device detects the optical frequency deviation of the input light as differential photocurrent from the dual photodiodes, and the photocurrent is fedback to the light source for frequency stabilization through a differential amplifier. The FSR and extinction ratio of the filter are 50 GHz and 20 dB. The total opto-electronic conversion efficiency is 40%. In a frequency stabilization experiment using the developed discriminator, the frequency fluctuation of a DFB laser was reduced to less than 10 MHz.