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We present broadband MMI couplers, developed for a novel integration platform on InP with active/passive integration capabilities for the 1300nm wavelength range. Low loss (

We demonstrate the generation of radio-frequency (RF) signals using stabilized integrated semiconductor lasers. The lasers are monolithically integrated on the same chip using InP active-passive integration technology. They are locked to different resonances of the same external optical cavity using the Pound-Drever-Hall locking technique. The locking is implement with single control loop for each laser and by voltage controlled tuning thus avoiding significant thermal effects. The generated RF signal can be tuned discretely to frequencies that are multiples of the external optical cavity free spectral range. Examples of beat tones at 12.436, 24.8735 and 40.4194 GHz are demonstrated. The linewidth of the generated signals at all frequencies is less than 40 kHz. The single-side-band phase noise is about -54 dBc/Hz for frequencies offsets from the carrier at 12.436 GHz between 1 kHz and 10 kHz and -60 and -67 dBc/Hz at 100 kHz and 1 MHz respectively.

Residual amplitude modulation of the phase modulator deployed in Pound-Drever-Hall frequency stabilization is an effect known to cause instabilities to the absolute wavelength of the stabilized laser. We present measurements and analysis of the residual amplitude modulation in an InP-based waveguide electro-optic phase modulator. The modulator is monolithically integrated in the output waveguide of a tuneable laser. The effects on the frequency stabilization of such a laser system to a reference etalon using a Pound-Drever-Hall frequency stabilization scheme are quantified. Frequency offset values in the stabilization point from the reference Fabry-Perot etalon resonance caused by the amplitude modulation are predicted and optimum operating points to minimize residual amplitude modulation are discussed. By operating an electro-refractive phase modulator at the proper bias point we show that frequency offsets corresponding to less than 3×10 ^{-3}$ of the reference cavity full-width half-maximum can be achieved.

We demonstrate a monolithic extended cavity InP-based single-mode laser with DBR mirrors and an intra-cavity ring resonator with 15 mA threshold current fabricated with a generic integration technology. A 130 kHz linewidth has been measured and an SMSR well over 60dB.