Modeling of ultrawidely tunable vertical cavity air-gap filters and VCSELs

Role of Nanoimprint Lithography for Strongly Miniaturized Optical Spectrometers

“…A larger spectral range of 1.15–1.8 µm (650 nm span) can, e.g., be bridged using a small array of only three InGaAs photodiodes and three corresponding MEMS tunable filters, which are spectrally neighbored and each tuning range is over 220 nm respectively. Many different designs of MEMS tunable filters in various material systems have been reported [ 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ]. As an example, Figure 12a displays an SEM micrograph top-view of one of our InP-multiple airgap MEMS FP filters; circular central membranes are elastically fixed by four suspensions to four supporting posts.…”

“…The third interferometric spectrometer is based on the Fabry–Pérot (FP) principle [ 4 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ]. Although only two parallel transparent dielectric mirrors are involved, the FP interferometer is also highly complex and involves multipath interference.…”

“…As a selection of alternatives to these mini grating spectrometers, we compare in this review paper four strongly miniaturized optical spectrometers ( Table 1 ): AWG devices [ 20 , 21 , 22 , 23 , 24 , 25 , 26 ], static FP filter arrays on a charge-coupled device (CCD) or complementary metal oxide semiconductor (CMOS) sensor arrays [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ], tunable MEMS FP filter arrays [ 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 ] on photodetector (PD) arrays, and tunable MEMS photonic crystal (PC) filters [ 61 , 70 , 71 , 72 , 73 , 74 ]. At first glance, we identify that all these alternatives are smaller in size and reveal higher resolutions, as well as smaller FWHM than the grating spectrometers.…”

Wavelength trimming of MEMS VCSELs for post-process wavelength allocation

“…If we are able to realize athermal semiconductor lasers exhibiting a fixed wavelength under temperature changes, we expect low power consumption and small packaging in WDM transmitter modules. Tunable VCSELs with micro electro mechanical system (MEMS) have been studied intensively [1][2][3][4][5][6]. We reported the athermal operation of 1550nm VCSELs with a thermally actuated cantilever based on bimorph effect [7][8][9][10].…”

Sacrificial Al0.8Ga0.2As etching for microstructures in integrated optoelectronic devices

“…With micromachining technology, these semiconductor devices have demonstrated excellent properties for optical communication and spectroscopy applications. [1][2][3] For these optoelectronic devices, selective removal of Al x Ga 1−x As over GaAs has been a key process in their fabrication. Thus, understanding the properties of these lateral etching is important for the development of advanced optoelectronic and microelectronic devices.…”