Miniaturized tunable photonic devices can be of great interest for applications in wavelength division multiplexing systems or metrology applications. For a widespread deployment, such systems have to be compact, dynamically reconfigurable in wavelength, and with a low power consumption. To achieve such devices, many studies have been conducted in the past by using the MEMS technologies. However, MEMS solutions may have some drawbacks related to power consumption, high driving voltage or fragility of the MEMS structure. As an alternative to this MEMS approach, the use of the well-known and mature liquid crystals (LC) material within a monolithic microcavity structure has been proposed. In this work, we report InP based materials combined with LC microcells to achieve photodiodes or Vertical Cavity Surface Emitting Lasers (VCSEL) with tunable wavelength capabilities. In the case of photodetection experiments, a wavelength sweeping from 1480 nm to 1561 nm limited by the tuning range of a tunable laser used as a probe is demonstrated. This spectral window is covered with a LC driving voltage of 7V only, corresponding to an extremely low power consumption of few μW. The average sensitivity over the whole spectral range is 0.4 A/W, slightly lower than 0.6 A/W for similar photodiodes that do not integrate such a LC tunable filter. The quality of the filter integrated onto the surfaces of the photodiodes is constant over the full wavelength tuning range, showing a FWHM of 1.5 nm. For emission experiments, we developed tunable VCSEL integrating the same LC microcell technology than the one used for the photodiode. For this device, laser emission in CW operation has been demonstrated. This tunable VCSEL has been characterized under optical pumping with typical threshold very similar to the one obtained with single frequency device. This is an experimental evidence than optical losses introduced by the LC inserted in the VCSEL cavity are very low. Output power in the mW range is also demonstrated and by increasing the applied voltage up to 20 V, a wavelength tuning higher than 23 nm is achieved. For a better understanding of this behavior, thermo-optical simulations have been conducted. By taking into account the heating properties of the LC and the reduction in its birefringence with temperature, the wavelength shift as function of the voltage is completely reproduced. Recently, by using LC with a better thermal tolerance larger tuning ranges are expected.